It is only when the disease has progressed to the AIDS ____ a person begins to look sick.
Every time ______ I see the picture there, I think of my days in a remote mountain village.
Almost all the students were having classes when the earthquake _________.
______ more attention, the tree could have grown better.
Tom, you _____ leave all your clothes on the floor like this!
We have to work hard, ______ we’ll lose the chance.