承包商应在检验日期前( )天向工程师发出竣工检验通知。
A.21
B.24
C.27
D.28
参考答案:A
The old man has ______ beard.[ ]
A. a
B. an
C. the
D. /
I have some pens, some books ____ some cards. [ ]
A. of
B. is
C. and
D. with