Have you ever worked as______volunteer during the COVID﹣19 pandemic （新冠疫情）？
Yes． It was_____unforgettable experience for me．（ ）
| A． |
an； an |
B． |
an；a |
C． |
a； an |
D． |
a；a |
They offered courses _________ students know the importance of protecting the Huanghe River．（ ）
A．helpB．helpedC．helpsD．to help
Compared with a 1﹣day weekend， a 2﹣day weekend is ____ as we may have enough time for our hobbies．（ ）
A．more pleasantB．less pleasant
C．the most pleasantD．the least pleasant
As soon as books ______， the volunteers posted them to the students in Hope Primary School．（ ）
A．are raisedB．were raised
C．raisedD．have raised
The children are jumping excitedly because they have _______ the design perfectly in groups．（ ）
A．completedB．controlledC．contactedD．caused
Max got lost and was trapped in the forest for 10 hours _______ a farmer nearby found him．（ ）
A．ifB．sinceC．untilD．after