Think before you write you will get good grades in the exam.A. orB. thoughC. andD. but

问题补充：

Think before you write, you will get good grades in the exam.

A. or

B. though

C. and

D. but

答案：

A. or

B. though

(答案→)C. and

D. but

解析：or 是否，或者；though虽然，尽管；and和，并且；but但是，可是；句意：在动笔前认真想想，在考试中你就会取得好的成绩。结合语境可知上下文是顺接关系，故选C。