he was very tired，he continued working in his office．（ ）
A．BecauseB．SinceC．Although
Be careful!Don't walk on the grass，________ it will"cry"．（ ）
A．andB．butC．orD．so
Look at the"No Photos"sign．You ________ take photos in the art museum．（ ）
A．shouldB．canC．needn'tD．mustn't
To keep children away from danger，we warn parents ________ children at home alone．（ ）
A．leaveB．to leave
C．not leaveD．not to leave
Computers are very useful．They can help us get much ________ on the Internet．（ ）
A．gamesB．information
C．courageD．messages
What's the meaning of"One Belt and One Road"？
Let me ________ the words in the new dictionary．（ ）
A．look atB．look forC．look afterD．look up