题干
—The new policy will help ______ more markets in this region．
—It will be more convenient to us．
A：put out
B：set sail
C：open up
答案(点此获取答案解析）
C
—The new policy will help ______ more markets in this region．
—It will be more convenient to us．
A：put out
B：set sail
C：open up
时刻，将一金属小球从弹簧正上方某一高度处由静止释放，小球落到弹簧上压缩弹簧到最低点，然后又被弹起离开弹簧，上升到一定高度后再下落，如此反复。通过安装在弹簧下端的压力传感器，测出这一过程弹簧弹力
随时间
变化的图像如图（乙）如示，则
