Listen! Tom ______________in the classroom. How beautiful his voice is!
A.has sung B.will sing C.is singing
—The accident taught me a ______________that I will never forget.
—I think we should always put safety in the first place.
A.lesson B.method C.skill
Linda is interested in ancient buildings, ______________when she saw the Fujian earth building（福建土楼）, she jumped with excitement.
A.or B.but C.so
When Mr. Li came in and saw the clean and tidy classroom, he was very satisfied and praised the students who were______________.
A.on time B.on business C.on duty
It's dangerous to play your cellphone while walking in the street because you ______________be knocked by a car.
A.must B.should C.may
The 2022 Winter Olympic Games will be held ______________Beijing, China. It will be another big event for us Chinese people.
A.in B.at C.on
