在弯道内急转方向盘，很容易引发交通事故。
参考答案：对
Seeing the happy ______ of children playing in the park, I’m full of joy and confidence in the future of our travel agency.
A．sight
B．view
C．sign
D．scene
多项式5a2b﹣ab+3a﹣1中，二次项的系数是（ ）．
