Find ways to praise your children often you’ll find they will open their hearts to you.A.

问题补充：

Find ways to praise your children often, you’ll find they will open their hearts to you.

A. till

B. or

C. and

D. but

答案：

A. till

B. or

(答案→)C. and

D. but

解析：考察连词。根据上句和下句的逻辑关系，很容易判断出上下句之间是并列关系，答案为C。