每个对象都维护了一个指向自身的指针，这个指针称为 [12] 指针
参考答案：this
Children who are not active or ________ diet is high in fat will gain weight quickly.[ ]
A. what
B. whose
C. which
D. that
A．a为动滑轮，B端钢缆受到滑轮组的拉力大小约为3G
B．a为动滑轮，B端钢缆受到滑轮组的拉力大小约为G
C．a、c为动滑轮，B端钢缆受到滑轮组的拉力大小约为3G
D．a、c为动滑轮，B端钢缆受到滑轮组的拉力大小约为G
G
G