下列各式中可用平方差公式分解因式的是[ ]
A.﹣a2b2+16
B.﹣a2b2﹣16
C.a2b2+16
D.(ab+16)2
答案:A
—Can you spell your family name, please?
—______. [ ]
A. My name is Mrs. Black
B. Yes, my name is Jim Green
C. Yes, B-L-A-C-K, Black
D. Yes, I'm not
天然气过滤器管道上有专门向其内充氮气的管路,其作用是在检修过滤器及天然气管道时向过滤器内充氮气以排尽过滤器及管道内的残气。()