估算89×30时，可以把______看成______，估算的结果是______．
89×30，
≈90×30，
=2700．
故答案为：89，90，2700．
妈妈今年a岁，小红今年b岁，十年后妈妈比小红大______岁．
The weakening housing market continued to take its（）on the industry.
A.toll
B.profit
C.insurance
D.security
