圆直 meaning in Chinese

roundy and straight

Friction characteristics of oscillatory laminar flow in straight tube
圆直管内层流振荡流的摩擦特性
Tight and straight
卷紧而圆直
Answer : because pole is very round straight , especially cement pole surface is slick , weight big , roll the most easily when assemble and unassemble and be carried , be like carelessly , injure a person possibly
答：由于电杆都很圆直，尤其是水泥电杆表面光滑，重量又大，在装卸和搬运时最易滚动，如不注重，就可能伤人。