I hear Johnson was badly injured in the accident.-________,let’s go and see him.[ ]

Scientists think that there _____ life on Earth for millions of years.

We are lucky to be among the generation of people who have ______ and experienced the great social changes in our country.

Now one of the most serious problems many people are worried about _____ on the lack of adequate housing space.

Do you think you will be able to finish your writing by five o’clock today—________. I’ll be busy with experients all day.