题目内容：

The fact that ants are fascinating insects has been known for some time. Now, scientists have discovered a large number of wood ants living in an abandoned underground storehouse in Templewo, Poland, despite having no obvious source of food.

Polish zoologist Wojciech Czechowski and his team began studying the underground colony in 2013. They found the ants built a 60-cm high nest in the soil directly over the storehouse vertical air pipe. As years passed, the metal covering on the pipe eroded, leaving behind a hole that thousands of worker ants accidentally slip into each day as they go about their daily chores. The scientists say that there are no sources of food in the storehouse. This means that the insects live in a state of near starvation.

In July 2015, the researchers disturbed part of the ant nest in search of larvae (幼虫), cocoons(茧), and queens. They found nothing, leading them to suspect that the lack of food and cold temperatures made reproduction impossible and that the group tending the nest is entirely made up of non-reproductive female workers. Their population is refilled every year, by a new rain of unfortunate ants that slide down the hole. The researchers say that when they returned in January 2016, the nest had been repaired. It appears that despite the terrible conditions, the worker ants do not stop constructing their nest.

Wood ants are known for their ability to adapt to bad living conditions. In this case, the millions of worker ants trapped in the storehouse have no choice. But instead of losing hope, they are making the best of the situation—a classic example of “when life gives you lesions make lemonade.”

1.How did the wood ants arrive in the storehouse?

A. They fell down there by accident.

B. The research team brought them there.

C. The storehouse builders left them there.

D. They were attracted by the environment.

2.What does the underlined word “eroded” in Paragraph 2 probably mean?

A. Expanded.    B. Rotted.    C. Exploded.    D. Melted.

3.What did the researchers find in the nest?

A. Larvae.    B. Cocoons.    C. A queen.    D. Worker ants.

4.Why did the population of wood ants remain steady?

A. They had enough food.

B. They were able to reproduce.

C. They adapted to the conditions.

D. They had new comers to join them.