商店有黄气球19个，红气球比黄气球少7个，花气球的个数是红气球的2倍，花气球有多少个？
（19-7）×2
=12×2，
=24（个）．
答：花气球有24个．
All Chinese people were very _____ at the _____ news happened on May 12th, 2008. [ ]
A. frustrated; frustrated
B. frustrated; frustrating
C. frustrating; frustrating
电源插座、接线板、电线的容量应满足电器功率的需要。
