题目

It was raining heavily. Little Tom felt cold so she stood ______ to her mother.  A. closely         B. closed          C. closing           D. close 答案：D如图所示的两光滑斜面AC＞BC，同一物体分别受拉力与作用从斜面底端沿斜面匀速运动到C点处，所做的功分别为、，则 [　　] A．， B．， C．， D．，