She that she had lost her purse.

位于费米能级附近的能级是有效的复合中心。

未知题型位于费米能级附近的能级是有效的复合中心。

Attention please. The plane will _________ in five minu...

单项选择题Attention please. The plane will _________ in five minutes.

When I"m nervous, it helps me to concentrate on some tr...

单项选择题When I"m nervous, it helps me to concentrate on some trivial activity, such as washing dishes or watching a game show.