I’ll go to your party you promise me that you will invite our class advisor.A. if onlyB. o

问题补充：

I’ll go to your party you promise me that you will invite our class advisor.

A. if only

B. only if

C. unless

D. since

答案：

A. if only

(答案→)B. only if

C. unless

D. since

解析：这题考查连词的用法：if only但愿，only if只有如果…unless除非，since自从，句意是：只有你答应邀请我们班的导师，我才去参加你的聚会。选B。