专利制度的本质是用技术的垄断权交换技术的公开。
参考答案:对
Jack wanted to read more, so he asked his friend if there was ________ to read.
A.something easy enough
B.something enough easy
C.enough easy something
D.easy enough something
肾气虚,胎失所系,可发生( )
A.滑胎B.不孕症C.带下过少D.经行浮肿E.子肿