某物体做直线运动的V﹣t图象如图所示,据此判断图(F表示物体所受合力)四个选项中正确的是( )
A:
B:
C:
D:
--- Will the new iphone cost a lot?--- I ________ think so. Apple's products are usually expensive.
日本自然资源贫乏,下列工业原料需全部从国外进口的有( )