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Hydroponics ______ the cultivation of plants without soil.A．doesB．isC．doD．are

Hydroponics ______ the cultivation of plants without soil.

A．does

B．is

C．do

D．are

提问人：网友xiaogang0805 发布时间：2022-01-06

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更多“Hydroponics ______ the cultiva…”相关的问题

第1题

Judging from the passage, the most important advantage of hydroponics should be______.A．hi

Judging from the passage, the most important advantage of hydroponics should be______.

A．higher yield

B．lower labor costs

C．more automation

D．less hard manual work

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第2题

One of the advantages of using hydroponics is increased pesticides and herbicides.A．RightB

One of the advantages of using hydroponics is increased pesticides and herbicides.

A．Right

B．Wrong

C．Not mentioned

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第3题

Which of the following statements is NOT true of hydroponics？A．Hydroponics is still too co

Which of the following statements is NOT true of hydroponics？

A．Hydroponics is still too complicated and expensive for practical use.

B．Hydroponics is considered a revolutionary method of agriculture.

C．Hydroponics has created wonders in agriculture.

D．Hydroponics has already been employed in food production.

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第4题

Why does the professor talk about the history of hydroponics？A．She wants to put the modern

Why does the professor talk about the history of hydroponics？

A．She wants to put the modern method in historical context.

B．She is trying to prove that hydroponics is a new idea.

C．She is following the information in the textbook very closely.

D．She digressed from the subject for a long time.

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第5题

The original hydroponics gardens merely consisted of plants floating in inert substances.A

The original hydroponics gardens merely consisted of plants floating in inert substances.

A．Right

B．Wrong

C．Not mentioned

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第6题

According to the professor, what is the greatest advantage of hydroponics？A．The plants are

According to the professor, what is the greatest advantage of hydroponics？

A．The plants are less likely to develop soil-borne diseases.

B．The cultivation requires much less labor than traditional methods.

C．The water can be recycled in a hydroponic environment.

D．Less space is needed to produce a large number of plants.

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第7题

According to paragraph 3, what is the advantage of hydroponics for research on nutrient de

ficiencies in plants？

A．It allows researchers to control what nutrients a plant receives.

B．It allows researchers to observe the growth of a large number of plants simultaneously.

C．It is possible to directly observe the roots of plants.

D．It is unnecessary to keep misting plants with nutrient solutions.

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第8题

Much of the research on nutrient deficiencies is based on growing plants hydro-ponically,

that is, in soilless liquid nutrient solutions. This technique allows researchers to create solutions that selectively omit certain nutrients and then observe the resulting effects on the plants. Hydroponics has applications beyond basic research, since it facilitates the growing of greenhouse vegetables during winter. Aeroponics, a technique in which plants are suspended and the roots misted with a nutrient solution, is another method for growing plants without soil.

The word "facilitates" in the passage is closest in meaning to

A．slows down

B．affects

C．makes easier

D．focuses on

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第9题

Hydroponics, the science of growing plants, in water or inert substances, represents one o

f the most innovative practices in modern agricultural development. Not only does it allow greater of the plant growth process, it permits the production of crops in hostile infertile environments.

The first widely publicized soilless gardening experiments were conducted during the 1930s. W. F. Gericke varied nutrient levels among specimens suspended in a gravel substrate (沙砾基质) to demonstrate remarkable alterations in growth. Among the findings that amazed his fellow horticulturists was the production of tomato plants over 6 meters high.

The original hydroponics gardens merely consisted of plants floating in water. It was later discovered that the roots could survive in a number of media, as long as they were supplied with sufficient moisture, nutrients and oxygen. A variety of materials are used in recent versions including gravel, sand, peat, sawdust, plastics and so on. Indeed, one of the most productive methods involves suspending plants in air with a Styrofoam support and spraying them occasionally with nutrient solution to keep them moist.

Many different kinds of materials are suitable for physically containing plants, yet all of these systems share one trait: the culture solution. This nutrient bath is prepared in a tank by dissolving salts which provide the necessary chemicals for plant metabolism. Constant care must be taken to assure that the sodium chloride(氯化纳)levels in the tank do not reach excessive levels as the plants draw water and minerals out of the solution. The acidity of the tank must also be maintained around 6.0 to 6.5 depending on the specific type of plants being harvested.

Although soilless farming is generally more expensive than utilizing fertile land, there are many advantages that make it an important alternative to traditional practices. Herbicides and pesticides are unnecessary because of the controlled environment. The plants also need less space to grow because their nutrient uptake is significantly more efficient. The most outstanding benefit, though, is the ability to produce crops in areas with poor soil conditions or insufficient rainfall.

Earth is mentioned by the author as a necessity for hydroponics.

A．Right

B．Wrong

C．Not mentioned

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第10题

In 1798 the political economist Malthus predicted that in time mankind would face starvati

on, having outgrown the available food supplies. Today, a century and a half later, there are still experts who forecast the same global disaster—unless urgent measures are taken to prevent it. By the end of the present century there may well be over five thousand million people living on this globe, an increase of over fifty percent on todays figure. In order to keep pace with this increase in mankind the farmers of the world will have to step up their production of food by at least two percent every year. Such a rate of increase has never been maintained in any country by conventional methods of agriculture, despite modern mechanization and the widespread use of fertilizers. There are no large worthwhile reserves of potential farmland remaining, and good fertile land is continually being changed into industrial use. Moreover, erosion of the soil takes a constant toll (损失). Intensive research, carried out over many years in all manners of climate conditions, has produced a revolutionary method of growing crops without using any soil at all. Hydroponics (水栽法), as this technique is called, may well be the answer to all our food worries; already it has accomplished wonders in producing huge crops. Hydroponics was once a complicated and expensive business, now it is well out of the experimental stage. Labor costs are far lower than when normal methods of agriculture are employed. In fact, it is a completely automatic system. There is no hard manual work, no digging or ploughing, and no weeding to speak of. Yields can be far higher than they are in soil.

Which of the following best sums up the whole passage？

A．Malthus" prediction has been proved to be correct by modern experts.

B．Hydroponics is a new development in agriculture.

C．Hydroponics may be the answer to the world food shortage in the future.

D．Conventional methods of agriculture should be improved so as to step up food production by two percent every year.

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