下列关于封闭式基金的说法正确的有（）。

沾染(contamination)

食品污染(food contamination)

().

A.total dissolved solids

B.salt contamination

C.water harcness

D.chlorine contamination

A．地面沾染程度

B．沾染面积

C．沾染高度

D．风向

A salinity indicator is used to determine the _____.

A.cause of salt contamination

B.location of salt water contamination

C.chemical makeup of feed-water

D.level of alkalinity in condensate

Diesel engine fuel oil contamination often results in ______.

A.governor malfunctions

B.fuel injection system malfunctions

C.high cylinder lube oil temperatures

D.low intake temperatures

l regulations requiring a drop in industrial discharges of lead went into effect in 1975, but the major cause of the decline was a 75 percent drop in the use of leaded gasoline between 1975 and 19Which of the following, if true, best supports the claim that the major cause of the decline in the level of lead contamination in United States rives was the decline in the use of leaded gasoline？

A．The level of lead contamination in United States rivers fell sharply in both 1975 and 1983.

B．Most of the decline in industrial discharges of lead occurred before 1976, but the largest decline in the level of river contamination occurred between 1980 and 1985.

C．Levels of lead contamination in rivers fell sharply in 1975 - 1976 and rose very slightly over the next nine years.

D．Levels of lead contamination rose in those rivers where there was reduced river flow due to drought.

E．Although the use of leaded gasoline declined 75 percent between 1975 and 1985, 80 percent of the decline took place in 1985.

英译汉：“contamination”，正确的翻译为()。

A．浓度

B．污染

C．含量

D．成分