201×24
37×99+37
125×（7×8）
25×7×5×4
138×72﹣72×38
12×97+12×3．
=（200+1）×24
=200×24+1×24
=4800+24
=4824；
②37×99+37
=37×（99+1）
=37×100
=3700；
③125×（7×8）
=125×8×7
=1000×7
=7000；
④25×7×5×4
=（25×4）×（7×5）
=100×35
=3500；<
内战爆发后，人民解放军的作战原则是( )
— Where is Mary?
—I don ' t know. I haven't _________ her for a long time.
小黄测得自己每分种的脉动次数为70次，他用脉搏作为计时工具，测得从跑道的一端走到另一端的脉动次数是140 次，则他用的时间约为____秒．
从方框中选择恰当的语句，补全对话。
A.Yes, she is.
B.He's my brother.
C.No, he isn't.
D.He's my brother.
Cheng Jie: Who's that boy?
Amy:____
Cheng Jie: Is she your mother?
Cheng Jie: Is he your father?
