You must not think that when swallows fly over your head, they aren't working. No! Life is work to them. The young swallows eat a lot and they are busy catching the insects for them. So they have to work from early morning till late at night. At last the young birds can fly well, but the old ones can't rest. They began to think about their second family, for they have two broods every season.
When the second brood can fly, too, it's time to think about going to the warmer countries, and when spring comes, they'll return.
1．注解
(1) swallow n. 燕子
(2) nest n. 巢
(3) roof n. 屋顶
(4) lay v. 产（卵）
(5) insect n. 昆虫
(6) brood n. 一窝所孵的幼雏
2．思考题
(1) Can you see swallows easily now? Why?
(2) In what way can we protect (保护) this kind of animal?
dolphin
Long ago, dogs and horses were tamed to become man's helpers on land. Today some people believe that dolphins may become man's helpers in the sea .
Proof that a dolphin can be trained to assist man appeared in 1965. The U.S. Navy used the services of a seven-foot dolphin, Tuffy.
Tuffy worked with divers at the Navy's Man-in-the-Sea station off the coast of California. He acted as messenger to a ten-man team whose underwater home was Sealab II, 205 feet deep.
Wearing a plastic harness, Tuffy carried letters in a waterproof tube. He also carried tools for the undersea workers. Tuffy learned to answer calls for help. Pretending to be lost, an aquanaut would sound a buzzer. Another aquanaut would fasten one end of a line to Tuffy's harness .Tuffy would speed to the rescue.
More and more , it seems likely that old tales of dolphins' willingness to help man are closer to truth than to fiction .
1. The land animals dolphins are compared to are
A. oxen and horses B. dogs and cats
C. dogs and horses D. None of the above
2. The name of the trained dolphin was
A. Toughy B. Tuffy C. Tufty D. None of the above
3. The services of the dolphin were used by the
A. Government of California B. U.S. Army
C. U.S. Navy D. Scripps Institution of Oceanography
4. The article does not say that
A. the station was named Sealab II B. the station's depth was 205 feet
C. ten men were in the underwater team D. the men spent fifteen days at the station
5. For all his chores, the dolphin
A. wore a plastic harness B. carried a waterproof tube
C. carried a line D. carried tools
6. The signal for the dolphin's rescue chore was a
A. shout B. bell C. buzzer D. whistle
7. The purpose of the line the dolphin took was to
A. save the aquanaut from drowning
B. lead the aquanaut back to the others
C. help the aquanaut to guide the dolphin
D. carry a light to the aquanaut
8. The author suggests that this modern example makes old tales about dolphins seem