Students should to choose their own uniforms.A. allowB. allowedC. are allowedD. be allowe

问题补充：

Students should to choose their own uniforms.

A. allow

B. allowed

C. are allowed

D. be allowed

答案：

A. allow

B. allowed

C. are allowed

(答案→)D. be allowed

解析：句意：应该允许学生们自己选择他们的制服。本句中should是情态动词，后面动词用原形，学生们是允许的对象，故用被动语态。选D。