Yesterday our headmaster made a speech ______ environmental protection， and we learned something about recycling of waste．（ ）
A．onB．atC．to
Were you required___________ at home during the outbreak of COVID﹣19？
Yes． Luckily， the Internet made it possible for many of us________ from home．（ ）
A．to stay； to workB．staying； to work
C．to stay； workD．staying； work
To the west of our school__________ some bookstores and a park．（ ）
A．liesB．lieC．hasD．have
Millie's research paper isn't up to standard_________ she has worked at it for two weeks．（ ）
A．sinceB．unlessC．ifD．although
Take it easy． There will be_________ two buses coming in a few minutes．（ ）
A．anotherB．otherC．othersD．the other
Could you tell me ？
Yes. I bought it online.（ ）
A．where do you buy the sweater
B．where you buy the sweater
C．where did you buy the sweater
D．where you bought the sweater