高中英语冠词单句改错

They have their reasons for keeping their marriage a secret(保持他们的婚姻为一个秘密) for [the] momentNever lose [your?] heart; your health will be better day after day. 正确 正确 正确 正确 正确 Many people agree that [ ] knowledge(知识不可数,不能用a) of English is a must in the international trade today. The southerners usually have rice for [ ] lunch.(The在前面指的是southerners,lunch却不可以指为某一顿的午餐)正确