关于平衡与稳定的描述错误的是()A．人或物体的平衡与稳定是由其重量、支撑面的大小等多

She was scared ____ the yard because she was scared ___by the big dog ___ at the gate.

A．to go into; to be bitten; lay

B．of going into; to bite; lying

C．of going into; to bite; laying

D．to go into; of being bitten; lying

频繁呕吐、腹泻最易丢失的血清阳离子（）

A.钾离子

B.A和C

C.A和B

D.钙离子

E.钠离子

Every year in the U.S. , colleges and graduate schools continue to highly______trained people to compete for jobs that are not there. As a result, graduates cannot enter the professions for which they were trained.

A．turn out

B．work out

C．make out

D．bring out

气体保护焊电弧在保护气流的压缩下热量集中，焊接速度较快，熔池较小，热影响区窄。

（）在整个食物链是最高级的。

A.植物

B.动物

C.人

D.微生物