诊断颅底骨折最可靠的依据是（）
A.头颅X线片
B.脑电图检查
C.头部CT扫描
D.临床表现
E.头部外伤史
参考答案：D
--Has your teacher returned from America yet?
--Yes, but he _______ here for only three days before his company sent him to Africa．
A．was
B．has been
C．will be
D．would be
