Michael Jordan has failed over and over again in his life. And that is _______ he succeeds.

While he_____ on the phone, a man walked into his room.

_____is too hard _____ a good solution to this problem.

Can you possibly lend me fifty dollars until pay day? 　—______. Do you think I was born with a silver spoon in my mouth?

_______ is known to us, the dragon stands for China ______the bear symbolizes Russia.