Before __ the trunk must be checked.
A.used
B.to use
C.being used
D.to be used
答案:C
I think ________ vocabulary lists ________ us a lot.
A.make, help
B.making, helps
C.makes, helping
D.making, help
在计算机中,既可作为输入设备又可作为输出设备的是
A.显示器
B.磁盘驱动器
C.键盘
D.图形扫描仪