用一个5倍的放大镜看一个10度的角,那么看到的是50度的角.______.
用一个5倍的放大镜看一个10度的角,那么看到的仍然是10度的角.
故答案为:错误.
---_________ clever boy your brother is!
---So he is. He is_________ in my family.
A.What a; clever
B.What a; the cleverest
C.How;cleverer
D.How a; the cleverest
若x1、x2是方程x2-2x-1=0的两个根,则x1+x2+2x1x2的值为______.