题目

 People differ ________ one another _________their ability to handle stress. A. from; in       B. to; in              C. to; about        D. from; on 答案：A将一重100牛顿、边长为20厘米的均匀正方体，放置在水平的小桌面正中，如小桌面的边长为10厘米，则正方体对桌面压强是    ．