Why are there a lot of dead fish in the river?－Because they were ______ by the polluted water.

Now China is fighting against illegal cooking oil（地沟油）, a kind of waste oil _____can cause a lot of illness.

31. Tom__________ his father, because they both are cheerful and easygoing.

What kind of home does it _______? [ ]

Paul , please take this CD to ______ English teacher . —OK .