山峰的布局包括:单峰、双峰、三峰、多峰

在HF的-NMR波谱中，可以看到 （ ）。

A、质子的双峰

B、质子的单峰

C、质子的三重峰

D、质子和的双峰

A.1个单峰

B.3个单峰

C.2组峰：1个为单峰，1个为二重峰

D.2组峰：1个为三重峰，1个为五重峰

A、

B、

C、

D、

A、

B、

C、

D、

化合物CH₃COCH₂COOCH₂CH₃的¹HNMR谱的特点是(  )。

A．4个单峰  B．3个单峰，1个三重峰

C．2个单峰  D．2个单峰，1个三重峰和1个四重峰

A、n=4

B、n=3

C、n=2

D、n=1

A、boys than girls

B、girls than boys

C、boys than infants

D、girls than infants

Section A Reading in the Context Read the following passage with ten missing words. Learn to guess the meanings of them from the context and then select one word for each blank from the list of choices given in a word bank following the passage. Each word can be used only once. It is definitely time to take a closer look at digital marketing. There is a huge ____1____ in the number of Internet users who like to do everything from the personal computers or their mobile devices. So, when it comes to advertising and promoting your products and services online and for increasing sales and profit figures, nothing works better than digital marketing. In digital marketing, a business entity is promoted by using the digital mediums. This method of promotion helps in creating a ____2____ image of the business in the minds of the consumers. By employing unique Internet marketing tactics, more traffic can be generated, more conversion rates can take place and the return on ROI（投资回报率）can also be greater. Kolkata (加尔各答) is full of Internet marketing companies that offer unique marketing solution to both the ____3____ and the global clients. They hire senior Internet marketers who deal with complex projects. These people are extremely skilled and knowledgeable and help the business to rank high on the major search engines. They comprehend the business requirement of the clients and then derive marketing strategies to promote their brands. So, certain tips are available to spot the leading digital marketing agency: Experience is the ____4____ to success in this field. So, ensure that the digital marketing company you are hiring has senior and experienced digital marketers who understand the requirement of the clients. The company must keep the communication channel with their clients open so that the clients can interact with the professionals whenever the need ____5____. The project must be completed within the required timeframe that is set in the contract. A. domestic B. increase C. decrease D. key E. arises F. raises G. overseas H. positive I. hardly J. enhancing 注意：此部分填写所选答案的大写字母编号即可，不需填写具体的单词。请勿输入空格键。 1. _____________

A、low literacy in key target groups

B、cocaine and alcohol addiction

C、technology advances

D、depression, anxiety and social phobia