1． 已知，3m+2n = 8，则8 m · 4 n = （ ）（以幂的形式表示）．
28
根据首字母完成单词。
1. When the boy is free, he often goes bike r_____.
2. He thinks about going s_____ in Hainan.
3. Every weekend he has to stay at home and b_____ her.
4. —Do you r_____ a bike to school?
—Yes I do.
5. —Tom,who are you going for vacation w_____?
—Mmm, my parents, of course.
关于总变差的说法正确的是（）。
A.等于已释变差和未释变差之差
B.等于已释变差与误差之差
C.等于已释变差和误差之和
D.等于已释变差和未释变差之和
he boy is free, he often goes bike r_____.