Our class _______ forty-five students, in other words, forty-five students ______ our class.
A：consists of, are made up of.
B：is consisted of, make up.
C：consists of, make up.
D：is consisted of, are made up of.
曾经热播的《中国远征军》是一部反映中国军队为支援在缅甸的英国盟军、保卫西南大后方而英勇战斗的电视剧。该剧主要情节发生的时期是( )
已知样本容量是40，在样本的频数分布直方图中各小矩形的高之比依次为3:2:4:1，则第二小组的频数为____，第四小组的频率为____．
