在施工阶段，混凝土搅拌机、振捣棒、电锯等昼间作业的噪声限值为( )dB(A)。
A．55 B．65 C．70 D．85
参考答案：C
—You see, “Food Safety” receives thousands of Internet hits a day.
—Obviously, it has become one of the _________ topics recently.
A．interesting
B．hot
C．most interesting
D．hottest
土体在挖掘后，组织破坏，体积增大，这种现象称为土的( )。
A．渗透性
B．宽
C．空隙比
D．可松性
