He sets us so difficult a problem_________ I couldn’t work out.
Many people believe if you are _______, better things will happen to you.
I’ve just read your blood test report and all seems OK, so there’s _______ to worry about.
--Could you help me with some math problems?--Sure. That’s _______ I’m here.
What _________ pity you didn’t go to ______ concert with us! It was so exciting!
—You cough so badly recently. Give up smoking, please!—__________. I think I am addicted to it.