Scientists are working hard to make _______ possible for people to live on Mars in the future.

How do you like the garden?—Well, it’s beautiful, but not as ______ beautiful as mine.[ ]

Betty writes ___________ than ___________ student in her classroom.

This morning when I walked by the park, I saw many children ___ there.

Simon, you look worried. What’s wrong with you?—Well, I a test and I’m waiting for the result.