Toefl

READING COMPREHENSION:

One of the most dangerous drugs for pregnant women to consume is alcohol. Because alcohol is delivered quickly into the blood and passes quickly into the tissues andmembranes, the human fetus is particularly vulnerable to (3) its effects. In fact, the negative effects on a fetus are so pronounced that babies born after exposure to alcohol are said to be suffering fromfetal alcohol syndrome.
As a pregnant woman drinks alcohol, the alcohol is passed into her bloodstream almost simultaneously. (6) Moreover, because the bloodstream of the fetus is inextricablytied to that of the mother, the alcohol passes directly into the bloodstream of the fetus as well. And, what is more, the concentration of alcohol in the fetus is exactly the same as in the mother.For the mother, this concentration is not a problem because her liver can remove one ounce of alcohol from her system per hour. However, 15 the fetus's liver is not completely developed (howdeveloped it is depends on its stage of development). The rate at which it is able to eliminate the alcohol from the blood of the fetus is much slower.
Eventually, the alcohol will be returned to themother's system by passing across the placenta, but this process is slow. By the time 20 this takes place, major neurological damage may have already occurred. Research has shown that as little as onedrink of alcohol can produce significant, irreversible damage to the fetus. Babies born after exposure to alcohol generally exhibit facial distortion, inability to concentrate, and difficulty inremembering. Simply speaking, it is imperative that pregnant women avoid alcohol.

1. What is the main topic of this reading?
(A) Women and drugs
(B) The dangers of pregnancy
(C) The fetus and alcohol(D) Drinking and the human body

2. In line 3, the word "its" refers to
(A) the fetus
(B) the blood
(C) the tissue
(D) the alcohol

3. In line 3, the word "pronounced" most closely means...