If you don't know the meaning of the words, you can look _____ in the dictionary.
A：at them
B：them up
C：after them
D：them down
我们知道，长方形绕着它的一边旋转形成圆柱体，圆柱体的侧面展开图为长方形，现将一个长、宽分别为4cm和3cm的长方形绕着它的宽旋转一周，求形成的圆柱体的表面积．
