Questions 1 to 5 are based on the following conversation.

A． Certain waste products are vomited out of motorcars or out of factories.
B． The environment in general is being misused.
C． Some waste products are put into the air or the sea.
D． The publicity is only paid attention to.

A． Install Web filters.
B． Set Web sites.
C． Ban access to sites.
D． Block online service activities.