大量输库血引起凝血功能障碍的主要原因是血小板数降低。()
参考答案：错
碳氮共渗层的硬度比渗氮层硬度低，脆性小。( )
We are not ready to go into production yet, for the new switch mechanism isn’t fully ______.[ ]
A．tried out
B．tested out
C．worked out
D．turned out
