feifei－83

Some
cleaning fluids, synthetic carpets, wall paneling, and other products release
toxins, such as formaldehyde and benzene, into the household air supply. This
is not a problem in well-ventilated houses, but it is a problem in houses that
are so well insulated that they trap toxins as well as heat. Recent tests,
however, demonstrate that houseplants remove some household toxins from the air
and thereby eliminate their danger. In one test, 20 large plants eliminated
formaldehyde from a small, well-insulated house.

83.
Assume that a person who lives in a small, well-insulated house that contains
toxin-releasing products places houseplants, such as those tested, in the
house.

Which
one of the following can be expected as a result?

A.     
There will no longer be any
need to ventilate the house.

B.     
The concentration of toxins
in the household air supply will remain the same.

C.     
The house will be warm and
have a sage air supply.

D.     
If there is formaldehyde in
the household air supply, its level will decrease.

E.     
If formaldehyde benzene are
being released of each will decrease. 

选项e是什么意思啊。。。。。？