保护地内的蔬菜氨气中毒现象一般发生在施肥后（）。
A.几小时内
B.1～2d内
C.3～4d内
D.半月内
参考答案：C
We hope that the measures to control the stock
market, ____ are taken by the government, will work.
A．that
B．where
C．which
D．what
金属原始晶粒越细，储有能越低，再结晶温度低
