类黑素的反应与pH值有关,pH为()时最有利于类黑素的形成。
A.3
B.5
C.6
D.7
参考答案:B
The project tumed out to be very good, _ was more than we could expect. [ ]
A. what
B. that
C. which
D. this
流转税不包括( )。
A.增值税
B.营业税
C.契税
D.关税