—How about paying a visit to Mr. Richardson, our former history teacher?—Good idea. I will e-mail him today so he ___ know ___ to expect us.
________ I forget, please remind me about it.
Take your umbrella just ________ it rains.
Be quiet _______ you should wake the baby.
Take a hat with you in case the sun is very hot.
I’ll keep his address _____ I need it.