Can sixteen - year -olds drive their cars to go to school?-No they should’t becaus

问题补充：

--- Can sixteen - year -olds drive their cars to go to school?

---No, they should’t because they aren’t serious

enough.

A.allow B.be allowed C.have allowed

答案：

解析：从上下文意思来看，they是许可的对象，因此应用被动语态。