预防实验动物呼吸道不畅,最简单易行的办法是()。
A.气管内插管
B.将动物头部偏转一侧,舌牵出口角外
C.及时清除呼吸道分泌物
D.清除胃逆流物
E.放置口咽通气道
参考答案:B
Have you returned the book to the library ____?
--- Yes, I have ____ returned it.
A.yet, yet
B.already, already
C.already, yet
D.yet, already
隶书分为()、()两种。