对生物科学的探究常用的方法有__________、_________、_______________、___________。
观察 调查 收集和分析资料 实验
哪些情况需制作承力索的接头?
The audience were so ______ by his humorous performance that they kept laughing all the time.
A.moved
B.frightened
C.entertained
D.shocked