1、根据（x-y)(x+y）=x^2-y^2,用(x-y)(x+y)做外项,写成比例式为__________
问题描述：
1、根据（x-y)(x+y）=x^2-y^2,用(x-y)(x+y)做外项,写成比例式为__________
2、化简：√[2x+13+√(128x-192)]-√[2x-2+√(8x-12)](请提供解题思路或者过程）
3、设√（23-√448）的整数部分为a,小数部分为b,求a^2-b^2的值.（同上）
4、Mary was born _____ the morning____July 12
A.on...in B.in...on C.on...of D.of...on
5、I prefer _______ to _______ .
A.read books.watch TV
B.reading books.watch TV
C.to read books.watch TV
D.reading books.watching TV
答
4.C
5.D