中国农村社会学的产生和发展

My cousin went to Canada two yours ago. He ______ there for a few months and then went to America.

A．worked

B．would work

C．would be working

D．has been working

以下关于牙槽骨吸收的描述，哪项不对

A．牙齿松动程度，Ⅱ度以上松动为有 吸收

B．牙周袋深度大于4mm的真性牙周袋 为有骨吸收

C．牙槽嵴顶到釉牙本质界的距离，超过 2mm可确定有骨吸收

D．X线示牙槽骨与牙根面问形成角形 骨缺损

E．以上均不对

The news spread quickly through the village _______ the war had ended, _______ made villagers wild with joy.

A．which; that

B．that; what

C．that; which

D．what; which

对儿童语言发育的描述不正确的是()

A．4个月会笑出声

B．6个月能无意识发“爸爸”等复音

C．9个月能懂“再见”等

D．12个月能叫出物品名字，如“灯”

E．15个月能说出自己的名字

形成黄土高原水土流失的物源和触发机制是    (    )

A．轮荒耕作

B．植被破坏

C．地下开挖矿井

D．大面积开挖原生地面，露天开矿