先化简，再求值：
2x3-（7x2-9x）-2（x3-3x2+4x），其中x=-1。
解：原式=
当x=-1时，原式=-2。
It looks as if they were going to us 3,000 dollars for the concert hall.
A．want
B．charge
C．demand
D．cost
--- The couple _______ after 10 years’ marriage.
--- What a pity. Their child may suffer a lot from this.
A．broke out
B．broke down
C．broke up
D．broke into
