I’m sure that you will succeed in the end ___________ you give up halfway.

下列各组词语中加点的字注音有两个错误的一项是（ ）

think 3,000 yuan is enough to ______his needs for the tour to Beijing

More than fifty students competed _______each other in the composition competition—But they could only compete _______three medals

_____ do they exercise— Twice a week.