原油按其含胶质分类,当含胶质为5%~15%时,该原油属于()。
A、低胶原油
B、含胶原油
C、多胶原油
D、特高胶原油
参考答案:B
用适当的短语完成句子。
hear of, drop out of school, look after, look out, go abroad, be different from
1. His family is very poor,so his parents want him to______.
2. In order to improve his foreign language, Li Lei______last month.
3. ______!The car is coming.
4. Her character is mine.She is______introvert (内向), but I am the opposite.
5. Do you______Coco, she is a very famous singer.
6. Please______your grandparents,they are too old.
构成传染病流行过程的三个基本条件是( )。
A.微生物,宿主,媒介
B.传染源,传播途径,易感人群
C.病原体,环境,宿主
D.病原体数量,致病力,定位
E.病原体,人体,他们所处的环境