--Have you got the leaving time of the train for me?---Yes but you’d better of it by your

问题补充：

--Have you got the leaving time of the train for me?

---Yes, but you’d better of it by yourself.

A. make sure

B. be sure

C. to make sure

D. be certain

答案：

(答案→)A. make sure

B. be sure

C. to make sure

D. be certain

解析：考查词组：A. make sure确保B. be sure和 be certain一定，有把握，had better后面接动词原形，句意：--你知道火车什么时候离开吗？--是的，你最好自己核实一下。选A。