28.I had wanted to help you last night but I couldn't spare any time.for I_____an essay that is due this morning.
--- Beautiful day, isn’t it? Shall we go out for a picnic? --- ________!
It’s _______ you do today that will make a difference in your life tomorrow.
Mr Green showed his students some photos ________ at World Expo 2010 Shanghai.
A group of children are looking into the box, ________ about what can be inside.
I must be off now. My friends ________ outside.