期中测验，小芸的成绩较过去比有了很大的退步。她及时查找了自己的问题，积极向同学寻求更理想的学习方法。对小芸的行为，我们认识正确的是（  ）

在阿富汗战争，伊拉克战争和重大国际事件中，英国与美国结成伙伴，而在历史上英美两国的关系却并非一直如此，甚至发生过战争，这场战争是（  ）

如图甲所示，在平静的湖面下有一个点光源s，它发出的是两种不同颜色的a光和b光，在水面上形成了一个被照亮的圆形区域，该区域的中间为由ab两种单色光所构成的复色光的圆形区域，周边为环状区域，且为a光的颜色（图乙为俯视图）。则以下说法中正确的是(     )

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Never try to work when you are very hungry. If you decided to do your homework right after school, you may get something to eat before getting to work. Always do your homework before you get too tired. Don't wait until very late in everything, or your work will seem much harder than it really is.

    If you have more than an hour's work, give yourself a break after an hour. On the other hand, don't break it up so much, or you can't finish anything, you should be able to work at least a half at a time without stopping.

    Don't put it off until the last minute. If you put off doing your homework, you will have it on your mind, and you will not enjoy your free time so much. If you put it off until the end of the week or until right before a test, you will have too much work to do. A little bit each night, enough to keep up with what is happening each day in school, will make you not afraid of the test and get good grades.

Do your homework at the same time every evening. This will help you make it a habit. It will make it easier to do, and it will make your free time more enjoyable, as well.