题目内容：

Have you ever heard of an insect called the cicada(蝉)? 1. But they have an interesting internal clock that tells them when to go aboveground.

Every 17 years, billions of the noisy Brood V cicadas(十七年蝉) will swarm(成群出现) to northeastern parts of the US, including New York, Ohio and Pennsylvania. 2.But there are usually a lot less of them compared to the Brood V cicadas.

3. According to Discovery News, these insects started their lives in 1999. And as their 17-year life cycle comes to an end, they go aboveground when their underground homes get warmer 64 degrees Fahrenheit (about 18℃) to be exact.

Then the females will lay hundreds of eggs in trees, and after about four to six weeks, the mother and father cicadas will die. 4.

While they can be kind of annoying, these insects don’t harm humans, but they do make a lot of noise during their time aboveground. 5.

However, since there are so many of the 17-year cicadas, the amount of laid eggs can sometimes harm small trees and bushes. But after this summer, these insects will mostly mind their own business until 2033.

A. That sound is the male cicadas attracting the female cicadas.

B. The cicada insects are common in summer, especially in August and can be found in July as well.

C. There are other kinds of cicadas that come around once a year or every 13 years.

D. The baby cicadas will go underground, and the 17-year cycle will start over again.

E. As a matter of fact, people like to eat them in some cultures.

F. Well, a special kind of these insects live underground in the US for most of their lives.

G. This is what makes Brood V cicadas so special.