题目内容
（请给出正确答案）
[主观题]
Dust generated by compressed air （bailing airflow) flushing the drill cuttings from the hole being drilled.
提问人：网友gggg614
发布时间：2022-01-07
如搜索结果不匹配，请 
A、use
B、to use
C、used
D、to be used
题目内容
（请给出正确答案）
您可能会需要：
安装简答题APP，拍照搜题省时又省心！
更多“Dust generated by compressed a…”相关的问题
第2题
Respirable dust generated by outby sources can not enter the ventilating airstream and remain airborne across the entire longwall face.
第3题
Which is the potential character of a hazardous waste?
A、Corrosivity
B、Toxicity
C、Ignitability
D、Reactivity and Infectivity
第5题
(I) Capital market securities fall into two categories: bonds and stocks. (II) Long-term bonds include government bonds and long-term notes, municipal bonds, and corporate bonds.
A、(I) is true, (II) false.
B、(I) is false, (II) true.
C、Both are true.
D、Both are false.
第6题
Why does Mencken use the word “libido” in his title?
A、The word suggests that Americans’ passion for ugliness is a kind of pathological problem.
B、The title implies that his observations have a scientific foundation.
C、Mencken intends to ridicule Americans’ absurd desire for ugliness.
D、All of the above.
第7题
What makes it rain? Rain falls from clouds for the same reason anything falls to Earth. The Earth's Gravity(重力) pulls it. But every cloud is made of water droplets or ice crystals. Why doesn't rain or snow fall constantly from all clouds? The droplets or ice crystals in clouds are exceedingly small. The effect of gravity on them is minute. Air currents move and lift droplets so that the net downward displacement is zero, even though the droplets are in constant motion.
点击查看答案
Droplets and ice crystals behave somewhat like dust in the air made visible in a shaft(束) of sunlight. To the casual observer, dust seems to act in a totally random fashion, moving about wildly without fixed direction. But in fact dust particles are much larger than water droplets and they finally fall. The cloud droplet of average size is only 1/2,500 inch in diameter. (78)It is so small that it would take sixteen hours to fall half a mile in perfectly still air, and it does not fall out of moving air at all. Only when the droplet grows to a diameter of 1/125 inch or larger can it fall form. the cloud. The average raindrop contains a million times as much water as a tiny cloud droplet. The growth of a cloud droplet to a size large enough to fall out is the cause of rain.
What is the main topic of the passage?
A．The mechanics of rain.
B．The climate of North America.
C．How gravity affects air current.
D．Types of clouds.
第8题
Enclosed cabs with , , and systems are typically integrated into the drills and mobile equipment to protect the operator from the outside environment.
A、heating
B、ventilation
C、drill stem
D、air conditioning
