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下图为“以南极为中心的地球俯视图”，弧线a表示晨昏线，阴影部分表示黑夜，读图回答下列问题。

从图示节气到三个月后，A点正午太阳高度的变化是（）。

答案

参考答案：先变大，到最大90°，后变小

解析：

图中节气为冬至日，三个月后为春分日，A位于赤道和南回归线之间，故正午太阳高度角先变大，到最大90°，之后再变小。

考点：该题考查地球运动。

完形填空

根据短文内容及首字母提示，填写所缺单词，使短文意思完整，每空限填一词。

Good morning, ladies and gentlemen !

Today, I am very happy to have a meeting with you.  At the meeting we will talk about the p___小题1:___ we have these days.  We all know the problems of dogs and the objects falling from windows are getting worse.  We have already r__小题2:___ lots of letters about such problems.  So it is time for us to look for possible ways to s___小题3:___ these problems.

Some dog-owners don’t look after their dogs w___小题4:__ enough, and they let their dogs make mess on roads and in gardens. This makes the environment dirty.  I would like to tell the dog-owners that their b___小题5:___is too bad, and at the same time they are m___小题6:___ people feel unhappy.  We should keep the environment pleasant.

It is reported that some people throw rubbish out of windows. It is dangerous b___小题7:__ falling objects may hurt others.  It is also a___小题8:___ the law. We should put up a notice (布告、通告) to teach people not to do so.  If it is found, we will record the names and addresses of people who throw objects.  Then, a warning will be given and they will be p___小题9:___ by law.

A safe and comfortable living environment is important to us. If we t___小题10:___ our best to care for our community, it will be a good place to live in.

Thank you for your coming.
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选择题

李剑中午放学回到家中后，陪妈妈一起摘番茄，当他看到鲜红迷人的番茄时，忍不住摘了一个吃起来，这时他妈妈问他：“好吃吗？”他回答说：“好吃，又酸又甜真解渴。”你知道番茄中的酸味物质和甜味物质存在于下列哪种结构中吗？[ ]

A．细胞膜                              

B．细胞核      

C．叶绿体                              

D．液泡
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