The sky is much bluer ________ we have taken action to protect the environment．（ ）
| A． |
because |
B． |
before |
C． |
until |
D． |
unless |
—May I ________ your pen? I can’t find mine.
—Sure. Here you are.
| A． |
repair |
B． |
make |
C． |
borrow |
—Betty, you’d better follow the doctor’s ________ and do more exercise.
—I will. Thank you.
| A． |
advice |
B． |
agreement |
C． |
information |
Please ________ the lights when you leave the room. Be a greener person.
| A． |
turn off |
B． |
turn on |
C． |
turn up |
As the art festival is coming, they are preparing everything by ________.
| A． |
yourselves |
B． |
ourselves |
C． |
themselves |
________ May 2022, we held many events to celebrate the 100th birthday of the Communist Youth League of China.
| A． |
At |
B． |
In |
C． |
On |