题干

如图所示,用自制针孔照相机观察烛焰,有以下四句说法:

①薄膜上出现烛焰的像是倒立的

②薄膜上烛焰的像可能是缩小的也可能放大的

③保持小孔和烛焰的距离不变,向后拉动内筒增加筒长,烛焰的像变大

④保持小孔和烛焰的距离不变,向前推动内筒,烛焰的像更明亮

对于这四句说法,其中正确的是(   )

A:①②

B:③④

C:①③④

D:①②③④

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D

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    Sure, it's good to get along with your teacher because it makes the time you spend in the classroom more pleasant. And yes, it's good to get along with your teacher because, in general, it's smart to learn how to relate to the different types of people you'll meet throughout your life. But really, there's one super-important reason why you should get along with your teacher. Kids who get along with their teachers not only learn more, but they're more comfortable asking question and getting extra help. This makes it easier to understand new materials and do yours best on tests.

    When you have this kind of relationship with a teacher, he or she can be someone to turn to with problems, such as problems with learning or school issues.

    As a kid in elementary or middle school, you're at a wonderful stage in your life. You're like a sponge (海绵), able to suck up lots of new and exciting information. On top of that, you're able to think about all this information in new ways. Your teacher knows that, and in most cases, is thrilled to be the person who's giving you all that material and helping you put it together. Remember, teachers are people, too, and they feel great if you're open to what they're teaching you. That's why they wanted to be teachers in the first place to teach!

    Some kids may be able to learn in any setting, whether they like the teacher or not. But most kids are sensitive to the way they get along with the teacher, and if things aren't going well, they won't learn as well and won't enjoy being in class.