27
(A)run around
(B)running around
(C)are running around
(D)have been running around

Chile’s Atacama desert has been “super dry”--and has remained so--longer than any other place on Earth. The desert only sees rain two _____26_____ four times a century. Flies do not exist there because there is nothing to eat. There are no trees, no lakes, no little animals _____27_____ . Some areas have been dry for almost 40 million years. In some places of the desert, there are no human records of a single drop of rain. It is _____28_____ dry that when a person dies, his body does not go rotten. The desert is the only place in the world _____29_____ saltpeter can be found. Saltpeter is easily mixed with water and disappears in the water so the desert is perfect for _____30_____ it. In fact, scientists have found that the dry river beds in the desert have had no water running through them for 120,000 years.

There are no trees, no lakes, no little animals _running around 

改分詞 形容小動物。那裡沒有樹，沒有湖，沒有四處跑的小動物。可以想成 which 關代省略。