试题题干
The paragraph is followed by an incomplete phrase or sentence which summarizes the main idea of the paragraph. Choose the missing words of the phrase or sentence.
Inside your nose, there are hundreds of tiny hairs. These hairs filter the air you breathe. Sometimes dust and pollen find their way through these hairs and bother your nasal passages. The nerves in the lining of your nose tell your brain that something is invading your body. At this moment you usually sneeze.
An automatic （） of our body.
参考答案
正确答案：
试题解析
本段主要讲述的是打喷嚏是我们身体的本能反应。在你的鼻腔里，有数百根细小的毛发。这些毛发可以过滤你吸入的空气。有时，灰尘和花粉会通过这些毛发进入你的鼻腔并堵塞你的鼻道。你鼻子内部的神经就会告诉你的大脑你的身体被某些东西入侵了。这时，你通常会打喷嚏。reaction反应。