The firemen know _____ to do.
A:what
B:why
C:where
D:when
I can see _______ all. ( )
计算下列各式的值:
(1)(3+2)﹣2
(2)(﹣3)2﹣|﹣12|+12﹣9
(3)x2﹣121=0;
(4)(x﹣5)3+8=0.