专利申请人在授予专利权之前，随时可以主动要求撤回专利申请。
参考答案：对
蒸发盘管一般安装在（）。
A.角钢支架上
B.墙壁上
C.悬空吊环上
D.特别支架上
I ______ with a big party the help of my former classmates in preparation of the advertising firm.
A．exhibit
B．express
C．convey
D．acknowledge
