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【单选题】
It's polite for students _____ hello to teachers. [ ]A.
to say
B.
saying
C.
says
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【单选题】听力原文： Bad as well as good moods spice life and build character. The key is balance. We often have little control over when we are swept by emotion. But we can hove some say in how long that emotion wi...
A.
We can take control when we are swept by emotion.
B.
We can control the length of time emotion lasts.
C.
We can find the cause of emotion.
D.
We can prevent bad emotions from happening.
【简答题】分子间氢键一般具有 饱和 性和 方向 性,一般分子间形成氢键,物质的熔、沸点 (请填“增大”或“减小”) ,而分子内形成氢键,物质的熔、沸点往往 。
【单选题】关于氢键，下列说法正确的是 （ ）
A.
分子间形成的氢键使物质的熔点和沸点升高；
B.
冰中存在氢键，水中不存在氢键；
C.
每一个水分子内含有两个氢键；
D.
H 2 O是一种非常稳定的化合物，这是由于氢键所致
【单选题】听力原文： Sex education is a serious scientific subject, which is as important as the other sciences and arts subjects, even if it is not included in the exams, especially the college entrance examination...
A.
Many people will still regard sex education as embarrassing.
B.
Proper sex education is mentally helpful for teenagers' growth.
C.
Teenagers' chances to see psychological doctors have increased.
D.
Without the proper guidance of the teachers, no teenagers will grow healthily.
【单选题】听力原文：O.K. Here's your key. The elevator is down the hall to your right. Breakfast will be served from seven to eleven a.m. in the restaurant, which is down the stairs. The fitness room is from eight a...
A.
A key
B.
A receipt
C.
A city map
D.
A breakfast coupon
【单选题】关于氢键，下列说法正确的是( )
A.
每一个水分子内含有两个氢键
B.
冰、水和水蒸气中都存在氢键
C.
分子间形成的氢键使物质的熔点和沸点升高
D.
H 2 O是一种非常稳定的化合物，这是由于氢键所致
【单选题】听力原文：Had I known you didn't have a key, I wouldn't have locked the door. Which is true about the speaker's implication?
A.
I knew you have a key.
B.
I'm sorry I locked the door.
C.
I'm sorry I didn't lock the door.
D.
I didn't know you have a key.
【简答题】听力原文：What is the key point of traveling by plane? What is the key point of traveling by plane? It is to give yourself ______.
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