在CAD中在一个视口中，可以有多种样式的点样式（）
参考答案：错
某升降机上升了4米，表示为+4米，那么下降了3米，应记作______米．
A poem written by an American poet is usually harder to understand than ________ by a Chinese poet.[ ]
A. that
B. it
C. which
D. one
