请你在图中画出使用剪刀时,杠杆AOB所受动力F的示意图及动力臂L1、阻力臂L2.
过A点作杠杆的动力F1,再分析从支点向动力作用线和阻力作用线画出垂线,标上力臂.
So much ______ by the poem for the Wenchuan earthquake that he decided to participate in the re-construction of the damaged region.
A.did he move
B.he moved
C.was he moved
D.he was moved
先天性巨结肠行钡灌肠检查时,操作错误的是()
A.钡灌注量不宜过多
B.灌肠时压力不宜过大
C.检查完毕最好抽出钡剂
D.肛管不宜放置过高
E.先用肥皂水清洁灌肠