复式切板机停机时直接按下停止按钮即可停止设备。
参考答案：错
关于x的方程mx2＋3x＝x2＋4是一元二次方程，则m应满足条件是____。
—What's this in English?
—_____.[ ]
A. It's book.
B. This's a book.
C. It's a book.
