袁隆平是我国著名科学家，获第一届国家最高科技奖，其科研成果是（ ）
A．试管婴儿
B．克隆羊多莉
C．杂交稻
D．嫦娥二号
答案：C
--- I had thought he would be nervous in this speech competition, but he turned out to be calm.
--- He________quite enough preparation for it.
A．should do
B．must do
C．should have done
D．must have done
间接接触电击预防技术有哪几种？
