respect yourselves to high grades is the best way.A. To earn devote achievingB. Earn d

问题补充：

respect, yourselves to high grades is the best way.

A. To earn, devote, achieving

B. Earn, devoting, achieve

C. To earn, devoting, achieving

D. Earning, devote, achieve

答案：

A. To earn, devote, achieving

B. Earn, devoting, achieve

(答案→)C. To earn, devoting, achieving

D. Earning, devote, achieve

解析：整个句字已有谓语动词is，又没有连词故不能用谓语动词，排除B；动词不定式可以表目的。is前是主语，故用动名词短语，所以排除AD。to是介词后跟名词。故选C。