题目

 - Would you mind staying in such a noisy room?  - No, but my son needs a       place to study in. A.clean        B.quiet       C.safe       D.small 答案： B解方程：（1）7-2x=3-4x（2）18=140-x2（3）37x-0.9=27x+0.5（4）3（2x-1）=2（1-x）-1．