1.Erect: in an upright position straight 垂直的;竖直的;直立的
Stand with your arms by your side and your head erect. 手放两边,昂首站立。
2.Swing: to move backwards or forwards or from side to side while hanging from a fixed point; to make something do this (使)摆动,摇摆,摇荡
His arms swung as he walked. 他边走边摆着双臂。 V
A set of keys swung from her belt. 她腰带上挂着的一串钥匙摆来摆去。
As he pushed her, she swung higher and higher(= while sitting on a swing). 随着他推她,她在秋千上越荡越高。
He sat on the stool, swinging his legs. 他坐在凳子上晃动着两条腿。
3.Elasticity: the quality that something has of being able to stretch and return to its original size and shape (= of being elastic) 弹性;弹力
4.Bent: not straight 弯曲的
a piece of bent wire 一段弯曲的金属丝
Do this exercise with your knees bent(= not with your legs straight). 这个动作要求双膝弯曲。
5.Stiff: firm and difficult to bend or move 不易弯曲(或活动)的;硬的;挺的
stiff cardboard 硬纸板
a stiff brush 硬刷子
The windows were stiff and she couldn't get them open. 窗户紧,她开不开。
I've got a stiff neck. 我脖子发僵。