—_____ Even though the weather is very bad.
A:Yes, he is.
B:No, he isn't.
C:Yes, he isn't.
D:No, he is.
一个数减去45得19,这个数是( )。
已知m﹣n=﹣3,mn=4.
(1)求(3﹣m)(3+n)的值;
(2)求m4+n4的值.