We can get _______ touch with David on the Internet.A. in B. on C. to
—The party is a great success. We've had a good time. —______!
3D printers are still _____ expensive for most of us ______ afford.
The songs of the rock band sound ________.
Everyone passed the exam ________him. So he was sad.
I find ________ difficult to remember everything, though I’m still young.