HT20-40的HT表示（）。
A、HT—可锻铸铁
B、HT—球墨铸铁
C、HT—铸钢
D、HT—灰口铸铁
参考答案：D
补全对话。从所给句子中选择恰当的句子完成下面的对话
A: Let's play basketball, Jenny.
B: Sorry.__小题1:___ I just like computer games.
A: Do you have a computer game?
B: ____小题2:_____
A: Does your sister have a computer game?
B: _____小题3:____
A: OK. Why don't we have something to eat first and then play computer games together?
B: Good idea!
A: What do you like to eat?
B: _____小题4:_____
A: _____小题5:_____
B: She likes ice cream best.
丛集性头痛的特点不包括（）
A.单侧
B.疼痛程度剧烈
C.好发于女性
D.头痛可伴有结膜充血、瞳孔缩小等
E.没有先兆
