计算:(﹣2)2+[18﹣(﹣3)×2]÷4.
解:原式=4+24 ÷4
=10
travel can broaden your mind, I don't think it's a good idea to spend too much time and money on it . [ ]
A. If
B. While
C. Because
D. As
首先发现电流周围存在磁场的科学家是( )
A.焦耳
B.法拉第
C.奥斯特
D.赫兹