提高炉渣碱度,较低炉温及适当增加渣量有利于排碱。
参考答案:错
债是依照( ),在当事人之间产生的特定的权利和义务关系。
A.合同约定 B.合同约定或法律规定C.合同约定和法律规定 D.法律规定
It is required that students _____mobile phones at school, so seldom _____them using one.
A.don’t use; will you see
B.should not use; you will see
C.not use; will you see
D.can’t use; will you see