南、北美洲之间的分界线是。亚洲、非洲的分界线是_____。

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问题填空题

答案

巴拿马运河苏伊士运河

题目分析：南北美洲的分界线是巴拿马运河，亚洲和非洲的分界线是苏伊士运河。

问答题

按要求完成下列各题。

1. Sam: How about trying the new French restaurant tonight?

Tom: I heard it's very expensive.

Sam: Why don't we go Dutch?

Tom: Good idea!

Read the dialogue, can you guess the meaning of "go Dutch"? You may answer it in Chinese.

2. Sue is 5 years older than her younger brother Paul. Paul is 6 years older than Jim, the youngest in the family.

If the total of the children's ages is 32, how old is the eldest child?

3. What number should replace the question mark in the last circle?

4. Which letter should appear in the final medal?

5. Look at the shapes and codes given. Work out the code which matches the shape given at the end of the line.

多项选择题

以下对光纤的相关描述错误的是（）。

A、色散会使在光纤中传输的数字脉冲展宽，引起码间干扰，降低信号质量。

B、G.652光纤把最小的衰减与小的色散结合在一起，主要应用于本地网。

C、光在光纤中的传输速率为2×10m/s

D、理论上光线路信号在光纤上传送的波长为：850nm、1310nm、1490nm。