腹外疝的发病原因为
A.慢性咳嗽
B.长期便秘
C.排尿困难
D.腹壁有薄弱或腹壁缺损
E.经常从事导致腹腔内压增高的工作
参考答案:A,B,C,D,E
It is such a modem machine ____few of the workers know how to operate it.
A.which
B.that
C.as
D.the one
正言若反的若,其意是()
A.好像
B.假若
C.如此
D.就是