单项选择题
A．the box of bricks was heavier than him B．the box of bricks was lighter than him C．the box of bricks came down too fast D．the man was too careless
A．the box of bricks B．the ladder C．the top of the buliding D．the pulley
A．help people develop physically and psychologically B．make people feel sick C．cause people to be in the habit of taking them D．cause serious diseases