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问题 问答题

下列化合物分子中，在核磁共振1H谱图中能给出三种信号的是（　　）

A．CH3CH2CH3

B．CH3CH2OH

C．CH3CHO

D．CH3OCH3

答案

A、CH3CH2CH3中有2种H原子，核磁共振氢谱有2个吸收峰，故A错误；

B、CH3CH2OH中有3种H原子，核磁共振氢谱有3个吸收峰，故B正确；

C、CH3CHO中有2种H原子，核磁共振氢谱有2个吸收峰，故C错误；

D、CH3OCH3中有1种H原子，核磁共振氢谱有1个吸收峰，故D错误；

故选：B；

单项选择题

Are you interested in seeing the beautiful fall foliage of New England but tired of traffic jams and overbooked hotels Then this year forget the crowds in New England and see the beautiful colors of autumn in the Catskills.
These rugged mountains in New York State, just 90 miles northwest of New York City, are famous for the legendary tales of Rip Van Winkle, and more recently for the summer hotels mat sprang up in the region during the 1940s, 1950s, and 1960s. Families trying to escape the heat of New York City found the Catskills to be the perfect place to stay for a month or so each summer. By the late 1950s there were over 500 resorts and hotels offering nighttime entertainment as well as all kinds of outdoor activities. Famous comedies like Jackie Gleason, Joan Rivers, and Sid Caesar all got their start touring the hotel clubs here. Since the introduction of air-conditioning and cheaper air travel, however, families have stopped coming to the Catskills in such large numbers, chasing instead more distant locations at different times of the year. Many of the Catskills hotels closed in the 1970s, but some remain and have expanded and changed their facilities to meet the needs of today’s visitors.
Currently, there are many activities available to the traveler besides witnessing the changing colors of the leaves. There is an all-organic sheep farm where visitors can see how a traditional sheep farm operates. There are also hundreds of miles of scenic drives in the area. Route 42, for instance, is an excellent site for spotting bald eagles. For more information on vacations in the Catskills, call the office of Public Information.

From the passage, what might a visitor be lucky enough to do

A．See fall leaves in color.

B．See a kind of bird.

C．Work on a sheep farm.

D．Drive on scenic roads.
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问答题 简答题

“我的心就轻松起来，坦然地在潮湿的石路上走，月光底下。”中，“月光底下”是否可以作“走”的状语，为何它的位置要放在句末？
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