下列关于酶活性中心的叙述，正确的是

A．所有酶的活性中心都含有辅酶(或辅基)

B．酶的必需基团都位于活性中心之内

C．酶活性中心多隐藏在酶分子的内部

D．底物可引起酶活性中心构象发生改变

E．所有的抑制剂都作用于酶的活性中心

句型转换。

1. They send emails to their friends. (变为一般疑问句,作出肯定回答)

    —______ they ______ emails to their friends?

    —Yes, ______ ______ .

2. I live in Shanghai. (变为一般疑问句,作出肯定回答)

    —______  you ______ in Shanghai?

    —Yes, ______ ______ .

3. We use the computer at home. (变为一般疑问句,作出否定回答)

    —______ you ______ the computer at home?

    —No, ______ ______ .

4. Daming and Tom like playing computer games. (变为一般疑问句,作出否定回答)

    —______ Daming and Tom ______ playing computer games?

    —No, ______ ______ .