肩袖损伤最常见的临床症状是（）
A.疼痛
B.活动受限
C.无力
D.弹响
E.绞锁
参考答案：A
Although the living standards of Chinese people have greatly improved, most poor families in China spend 50% of their income on food.
A．gradually
B．approximately
C．harmfully
D．curiously
液压元件安装时应用什么清洗（）。
A.汽油
B.柴油
C.煤油
D.水
