石灰土应湿养，养生期不宜少于( )d，养生期应封闭交通。
A．4
B．5
C．6
D．7
参考答案：D
_____ he’s only been learning English for a year, he speaks it very well.
A．Considered
B．Considering
C．Having considered
D．To consider
All her time __________experiments, she has no time for films.
A．devoted to do
B．is devoted to doing
C．devoted to doing
D．is devoted to do
