阅读下面材料,在空白处填入适当的内容(1个单词)或括号内单词的正确形式。
People can often see a talking parrot on a TV show, in a movie, or even in someone’s home. The parrot has learned 1. (copy) sounds that people make. Dolphins, bats, and some apes also copy sounds. Now we can add elephants 2. this list of copycats (盲目的模仿者).
Dr. Joyce Poole is a zoologist, 3. studies the sounds of elephants. While she was in Kenya, she would hear strange noises 4. (make) by Mlaika after sunset. Mlaika was 5. 8-year-old African elephant 6. it lived near a highway.
Dr. Poole says that she couldn’t tell the difference between Mlaika’s call and the 7. (distance) truck noise. Why did 8. copy the sounds of the trucks driving by? Animals that are able to copy sounds may enjoy 9. (practice) new sounds. When they are kept outside of their natural environment, they may copy unusual sounds.
So far Dr. Poole 10. (spend) 18 years with two female Asian elephants. Asian elephants make sounds like birds to talk with one another.
Parrots, dolphins, humans, and elephants show that being a copycat is one way that animals and people make new friends and keep old ones.
Sam remembered several occasions in the past _____ he had experienced a similar feeling.
A. when B. which C. why D. that
— Coach, can I continue with the training?
— Sorry, you can’t _____ you haven’t recovered from the knee injury.
A. until B. before C. because D. unless
The water _____ cool when I jumped into the pool for morning exercise.
A. was felt B. is felt C. felt D. feels
— Hey! What's the rush?
— The plane _____ at 4:00 and I need to see my uncle off.
A. will take off B. takes off
C. has taken off D. took off
If we_____ the other road, we might have arrived here in time for the meeting.
A. take B. took
C. had taken D. have taken