English teachers are supposed their students a test in class even after class better tea

问题补充：

English teachers are supposed their students a test in class, even after class, better teaching results.

A. to give; ensuring

B. giving; to ensure

C. to give; to ensure

D. giving; ensuring

答案：

A. to give; ensuring

B. giving; to ensure

(答案→)C. to give; to ensure

D. giving; ensuring

解析：句意：英语老师理应让同学们在课堂上甚至是课后进行一次测试，来确保更好的教学效果。be supposed to do sth.理应干某事；后一空用动词不定式做目的状语。故选C。