拆检、清洗制动总缸、分缸时，皮碗、防尘罩发胀、老化或磨损（）。
A.应更换
B.应调整
C.应清洗
D.应检查
参考答案：A
留24小时尿标本做尿激素（17-羟类固醇）检查，应加入的防腐剂是（）
A.甲苯
B.浓盐酸
C.甲醛
D.高锰酸钾
E.碳酸氢钠
—May I speak to John?
—Sorry, he__________ Japan. But he__________ in two days.[ ]
A. has been to; will come back
B. has gone to; will be back
C. has been in; would come back
D. has gone to; won’t come back
