单项选择题
The main topic of the passage is （）
A．conditions in the work place B．the freedom of industries in the past C．changes in industrial production D．the safety and health of workers and customers
单项选择题 A suitable title for this passage might be （）
单项选择题 She didn't like()at the poor man.
单项选择题 has been done to prevent the water in the lake from being polluted.()
