在人们经常出现活动的地方,离地面1米处的场强要控制在()kV/m以内。
A.3~5
B.6~7
C.7~8
D.9~10
参考答案:A
指出下列句子中,哪一个划线单词的重音位置与其他划线单词不同,将序号填在括号内。
( ) 1. Remember to meet me at the library in the Republic Square the day after tomorrow.
A B C D
( ) 2. —Ask them to write a report about the programme.
A B C
—OK. That's a good idea.
D
( ) 3. A person with good manners should always be polite and helpful.
( ) 4. The computer is very useful today, for example,
A B
the librarian can use it to help you find the books on medicine easily in the library.
C D
( ) 5. At one time, there were long queues of people waiting outside the ticket offices of CAAC.
如图所示,红磷和硫分别在氧气中燃烧,待燃烧完毕后同时打开装置中的两个活塞,这时可观察到的现象是()
A.水迅速进入两个集气瓶
B.水只进入到A瓶中
C.水只进到B瓶中
D.两个瓶中都不能进水