仰拱和底板混凝土强度达到5Mpa后行人方可通行，达到设计强度的（）后方可车辆通行。
参考答案：100%
_____ on everyday practice, progress in English is a goal which can be achieved．
A．Based
B．Basing
C．Having based
D．Being based
方程x（x+2）=（x+2）的根为______．
