1 . Covid-19, the most deadly virus in recent years, began to attack people in 2019, from ________ effect people are still suffering. (用适当的词填空)

2 . Some American spellings were created by Noah Webster, ___________ made one of America’s first dictionaries. (用适当的词填空)

4 . I was moved to tears when I got a photo album from my parents, ________ reminded me of my happy childhood. (用适当的词填空)

5 . Swimming is good for teenagers, ______ some experts say will help them to stimulate their potential and promote their brain development. (用适当的词填空)

6 . In our school there are 50 students, half of __________ wear glasses. （用适当的词填空）

8 . ______ is known to all is that the old scientist, ______ Chinese people are proud of, is still devoted to advancing the medical development.

A．As; whom

B．What; whose

C．It; whose

D．What; whom

9 . I’ll never forget the days ______ I studied hard in my senior high school, ______ changed my whole life.

A．when; which

B．that; which

C．which; when

D．when; that

10 . He has a son, _____ has gone abroad for further study. (用适当的词填空)