句型转换。

1. There are forty women teachers in our school. (用last year改写句子)

     _______ forty women teachers in our school last year.

2. The children went back to school by bus. (改为同义句)

    The children _______ to school.

3. They saw some seals in the aquarium. (改为一般疑问句)

    _______ they _______ seals in the aquarium?

4. Lucy and Lily enjoyed themselves on the school trip. (改为同义句)

    Lucy and Lily _______ on the school trip.

5. We took lots of photos in the park. (改为否定句)

    We _______ lots of photos in the park.

6. Grace often goes shopping on weekends. (用last weekend改写句子)

    Grace _______ shopping last weekend.

下列降低风险的方法中，( )只能降低非系统性风险。

A．风险分散

B．风险转移

C．风险对冲

D．风险规避