帮我翻译成英文，不要机译~

The mental state of some of the students are not too great before test time.
It is difficult/hard for us to complete this task in such limited time.
"Have you cleaned up your room yet?" mother asked little Tom.
We need to take better advantages of these natural resources.
The government made a statement regarding its new policy this mroning.
What shocked us all was that he left home suddenly.
Mary's arrival to this city is very recent.
The second day we found that the earth was covered by snow.