用in +n.+of构成的短语的适当形式填空

1. Schools in the countryside are mostly                        good teachers.

2. Mr Brown is                      the company.

3. You had better take an umbrella                         rain.

4. You are right                            theory.

采用桁架挂篮施工时，在挂篮组拼后，应做（）。

A.动载试验

B.静载试验

C.拉力试验

D.破断试验