重要特性是指()
A.S=9~10
B.S=5~8&O>3
C.S=5~8&O>4
D.S=5~10
参考答案:B
I see four kinds of pressure working on college students today: economic pressure, parental pressure, peer pressure, but self-induced pressure.
A.and
B.or
C.nil
D.with
国家标准规定:普通水泥的终凝时间()。
A、≥6.5h
B、≥10h
C、≤6.5h
D、≤10h