Directions: In this section, there is a passage with ten blanks. You are required to select one word for each blank from a list of choices given in a word bank following the passage. Read the passage through carefully before making your choices. Each choice in the bank is identified by a letter. Please mark the corresponding letter for each item on Answer Sheet 2 with a single line through the centre. You may not use any of the words in the bank more than once.
Questionsare based on the following passage.
　　Health effects from indoor air pollutants may be experienced soon after exposure or, possibly, years later. Immediate effects may show up after a single exposure or repeated exposures. These include irritation (不适) of the eyes, nose, throat,headaches, dizziness, and fatigue. Such immediate effects are　1　short-term and treatable. Certain immediate effects are similar to those from colds or other viral (病毒性的) diseases, so it is often difficult to determine if the symptoms are a result of　2　to indoor air pollution. For this reason, it is important to pay attention to the time and place　3　occur.
　　Other health effects may show up either years after exposure has occurred or only after long or　4　periods of exposure. These effects, which　5　some breathing diseases, heart disease, and cancer, can be severely disabling or fatal. It is important to try to improve the indoor air quality in your home even if symptoms are not　6　.
　　While pollutants commonly found in indoor air are　7　for many harmful effects, there is considerable　8　about what concentrations or periods of exposure are necessary to produce specific health problems. People also react very differently to exposure to indoor air pollutants. Further research is　9　to better understand which health effects occur after exposure to the average pollutant concentrations found in homes and which occurs from the　10　concentrations that occur for short periods of time.
A ． uncertainty　　F ． repeated K ． symptoms
B ． lower　　G ． conditions　　L ． unconsciousness
C． exposure 　　H higher　　M． rarely
D ． show 　　I ． usually 　　N ． needed
E ． noticeable 　　J ． include　　 0 ． responsible
and fatigue. Such immediate effects are　1　short-term and treatable.