seventhree eight two five
2-two, 5-five, 7-seven, 3-three, 8-eight
做一个底面直径4分米,高5分米的圆柱铁皮通风管,需铁皮______平方分米.
CS2型手动操作机构分闸角度的调整,应调整拉杆部件。()