Tom has been out of work for two years, so he has difficulty______.
We have a high regard for Mr. Smith because he always tries to _____________his principles.
When he came back, he found the bag he had ______________ over the seat was gone.
We should be able to do the job for you quickly, ____________ you give us all the necessary information.
Jack could have avoided that terrible car accident, but he ________ careful enough.
The climate change conference has come to __________ end, but the developing countries are dissatisfied with __________ small step that the developed countries have taken to reduce the emission(排放) of water gases.