1. Quasars __________ emitting extremely intense radio waves and visible radiation.
(A) Star-like objects are
(B) Star-like, they are objects
(C) are star-like objects
(D) are they star-like objects
2. Mary Cassatt specialized __________ mothers with their children.
(A) painted
(B) who painted
(C) paintings
(D) in painting
3. Gorillas are quiet animals, __________ they are able to make about twenty different sounds.
(A) how
(B) in spite of
(C) because of
(D) even though
4. From 1946 to 1949, __________ William Henry Hastie served as governor of the Virgin Islands.
(A) the lawyer
(B) he was the lawyer
(C) the lawyer who
(D) was the lawyer
5. __________ struck, a tuning fork produces an almost pure tone, retaining its pitch over a long period of time.
(A) When is it
(B) One is
(C) When it is
(D) Is one
参考答案：
CBDAA