可能引起机械伤害的做法是( )。
A．正确使用防护设施
B．转动部件停稳前不进行操作
C．转动部件上少放物品
D．站位得当
参考答案：C
Jim’s brothers spent a whole day ________ in the aquarium. They forgot ________ back before ten o’clock.
A．hanging out; to come
B．hung out; coming
C．hang out; to come
D．to hang out, to come
酸中毒和缺氧对脑血管有哪些影响？
