The threats to the health of astronauts in space are very different from ______ on earth. 

I have two pens. One is red, and       is blue.

You’ve got so ________ housework to do. Can I help you, mum?

Graduation day is a very special day,        I’ll  never forget for the rest of my life.

—Betty told me the last mountainous bike you preferred to yesterday was bought by John.—Oh, my! How I regret that I didn’t buy ______.