德育过程要"反复抓,抓反复"所依据的德育规律是()。
A.知情意行诸因素统一发展规律
B.长期性和反复性规律
C.学生思想内部矛盾转化规律
D.在交往中形成品德规律
参考答案:B
Three people spoke at the meeting.____was a doctor; ____was a student; ___was a teacher.
A.He; she; I
B.The first; the other; the rest
C.One; another; the third
D.This; that; the last
粗脂肪测定中加入石油醚是为了除去乙醚中包容的水分。