1-（    ）²=（（    ）+（    ））（1-5y）；

（2x+3）²-x²=（    ）；

ab²-a=a（    ）；

x²-4y²+2x-4y=（x+2y+2）（    ）。

－I don't think Lily can sing _____ Lucy.

－I disagree. I think Lily can sing _____ Lucy. [ ]

A. as better as; as well as

B. as well as; worse than

C. so good as; better than

D. as well as; better than