—I think teenagers should to get their ears pierced.—I agree with you. A. are allowed B.

问题补充：

—I think teenagers should to get their ears pierced.

—I agree with you.

A. are allowed B. not be allowed C. not allowed

答案：

解析：考查被动语态。情态动词should的被动结构为should (not) be done结构，故选B项。