Millions of Chinese students watched Internet course ________ they stayed at home.
A.when B.until C.although D.before
Hurry! The online class ________ for ten minutes.
A.has begun B.has been on C.began D.was
—How will be the weather in summer in the south of China?
—It’ll be ________ .
A.colder B.hotter C.coldest D.hottest
During the outbreak（疫情）, we are supposed to ________ close contact with strangers.
A.allow B.avoid C.attack D.afford
The nurse took his temperature and found he had a ________ .
A.cancer B.cough C.fever D.flu
No matter what happens, children should learn to stay calm and protect ________ .
A.they B.them C.their D.themselves
