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

包装设计在需要以（）作为促销的首要元素的设计中，品牌的识别符号就应充分强化，使其易于辨认和识别。

A.标准字

B.标准色

C.品牌

D.理念