According to the ad，the book is for ().

单项选择题When the children are older, they ________.

单项选择题From the last paragraph of the passage we know that ________.

单项选择题According to the notice，people cant eat the fish from these waters mainly because ().

A．the fish is too small
B．the fish is too big
C．the fish is polluted by mercury
D．the fish is polluted by the water from factories

单项选择题When the children were very young, ________.

单项选择题Acid rain ________.