1 . “Solving ________ problem of plastic pollution is important. Landfill space is becoming limited,” says Wu, a Stanford University environmental engineering instructor. (用适当的词填空)

2 . Chinese hamburgers are very real and they predate ________ hamburgers we call our own in the U. S. (用适当的词填空)

3 . Our National Day is on ________ first day in ________ October.

A．a; the

B．the; a

C．the; /

D．a; /

4 . But after assessing ______ number of extant pandas in the late 1970s, China came to realize the fact that the animals had become a rare and endangered species. (用适当的词填空)

5 . You wouldn’t have caught such ________ bad cold if you hadn’t been caught in ________ rain.

A．a; /

B．a; a

C．a; the

D．/; /

6 . McGregor must stay in bed for a month on __________ basis of the medical reports his doctor has received. (用适当的词填空)

7 . ________ whole process was so smooth that Tang Hongbo was seen playing with the pen during the process of returning to earth. (用适当的词填空)

8 . The Beijing 2022 Olympic Winter Games opening ceremony began at the National Stadium in Beijing on the evening of February 4, 2022. ________ duration of the ceremony was reduced to about 100 minutes because of the cold weather and the COVID-19. (用适当的词填空)

9 . In old age, Mrs. Johnson became ________ most celebrated of the small excellent group of black women who at midcentury served as mathematicians for the space agency. （用适当的词填空）

10 . Online shopping was invented and pioneered by Michael Aldrich in ________ U.K. in 1979, while the Japanese operated the first modern high-speed rail in 1964. （用适当的词填空）