Question

【题目】—I wonder how much you charge for your services.

—The first two are free _____ the third costs $30.

A. while B. until C. when D. before

Answer 1

【答案】A

【解析】试题解析：

while:表转折 “而, 然而”句意:前两份免费,而第三份要$30。故选A