题目内容：

At 2:30 on December 5,1945, five US Navy training planes took off in clear weather from the base Lauderdale, Florida. The planes flew cast over the coast...and disappeared. The group was Flight 19, on a run between Florida and Bahamas. Tailor was the group leader. At about 3:40, Tailor reported that his compasses were not reading properly. The other planes followed their leaders aimlessly, first east, then west, then northeast over the ocean, as Tailor tried to make sure of the direction by radio. Then, suddenly Tailor was heard to give orders to dive...

Quickly, two giant Martin seaplanes were sent up to search for Flight 19. Several hours later, the wind became strong and visibility (能见度) dropped. A return to base was ordered. But only one of the Martin seaplanes landed. Four days later, the Navy and Coast Guard combed a 100,000 square miles area with more than 100 planes and ships. No sign was ever shown of the missing planes.

Today, people have noted the disappearance of many ships and planes in the southwest part of the North Atlantic and began to call this area the Bermuda Triangle(百慕大三角区).

The points of the triangle are Bermuda, Puerto Rico and a spot in the Gulf of Mexico, west of Florida. It is a two-faced water world of tiny islands, bright beaches and beautiful waters. Yet thick fogs, powerful currents(激流) and sudden storms are hidden behind this smiling surface.

1.Why did Flight 19 disappear?

A. Because the wind became strong and visibility dropped.

B. Because Tailor was given wrong orders to dive.

C. Because Tailor couldn’t read his compasses correctly.

D. Because something unknown made the compasses unable to work as usual.

2.In what position did Flight 19 disappear?

A. In the southwest part of the North Atlantic Ocean.

B. In the northeast part of the North Atlantic Ocean.

C. To the southwest part of Bermuda in the Atlantic Ocean.

D. To the northeast part of Bermuda in the Atlantic Ocean.

3.How many planes disappeared altogether that day?

A. Five.    B. Six.

C. two.    D. Only one.

4.The underlined word “combed” in the passage mean“      ”.

A. covered with    B. flew over

C. did up one’s hair with a comb    D. searched all over