偏头痛临床主要特点为（）.
A.半侧头痛
B.有先兆
C.搏动性跳痛
D.周期性发作性头痛
E.以上均不正确
参考答案：D
How long do you suppose ______ we applied for the job ________ we had been trained .
A．has it been since ; for which
B．is it before ; in which
C．it is when ; that
D．it is since ; for which
工程师有权通知承包人修改进度计划是在( )情况下。
A．只在实际进度滞后计划进度
B．只在实际进度超前计划进度
C．不论在实际进度超前还是滞后计划进度
D．在实际进行不能保证按时完成
