Straight or arched, thick or thin—eyebrows (眉毛) come in many shapes and sizes. But what are eyebrows even for? They don’t keep us warm like our hair, or help us breathe like our noses. So why do we have them? ____1____

Early humans had large brow ridges (眉骨). ____2____ Later, as the human face became smaller and flatter, our eyebrows helped us to express different feelings, as well as better understand others’ feelings. For example, a quick flash of the eyebrows... This is a sign that someone is willing to communicate with others, while pulling our eyebrows up in the middle is an expression of sympathy (同情). ____3____ just draw a simple face on a piece of paper and draw a line above the eyes. You can draw lines in different shapes and directions. You will find that it is very easy to show anger, fear or surprise on a face.

But this is not the only purpose of our eyebrows. ____4____ Their arched shape can help to move rain or sweat around to the sides of our faces, keeping our eyes dry. Together with our eyelashes (眼睫毛), eyebrows can also help to keep dust and other things out of our eyes.

____5____ In that case, some scientists believe that we would have developed some other facial feature to perform the same role. That could make us look quite different.

A. They can also protect our eyes.

B. What if we didn’t have eyebrows?

C. This helped them show their power.

D. If you still find this hard to understand,

E. Let’s take rolling one’s eyes as an example.

F. So far, no scientific research has found out the reason.

G. Scientists believe eyebrows helped us communicate better when we were still developing.

1.1.

A

B

C

D

解析：选G。前文抛出问题：人类为什么长眉毛？后文开始讲眉毛和情绪表达、沟通相关。G 选项 “科学家认为，在人类进化过程中，眉毛帮助我们更好地交流” 承接问句，引出下文，开启段落主题。

2.2.

A

B

C

D

解析：选C。前句：早期人类眉骨突出。C 选项 “这能帮助他们彰显力量”，代词 This 指代前文 “large brow ridges（突出眉骨）”，顺承介绍远古眉骨的作用。

3.3.

A

B

C

D

解析：选D。空格后是祈使句：在纸上画脸，画眉毛做实验。D “如果你还是难以理解这一点”，引出后面举例演示的内容，逻辑衔接词 if 引导条件，过渡自然。

4.4.

A

B

C

D

解析：选A。本段核心：眉毛保护眼睛，导流汗水雨水，阻挡灰尘。A “它们也可以保护我们的眼睛” 为本段中心句，also提示是眉毛的第二项功能，承接上一段沟通的作用。

5.5.

A

B

C

D

解析：选B。后文 “In that case（在这种情况下）” 指代空格内容，描述没有眉毛的假想结果。B“倘若我们没有眉毛会怎样？” 提出假设，和后文对应。