North Atlantic right whales now grow smaller than they did 40 years ago, and new research suggests a leading cause is the damage that human activity has done to the critically endangered species.

The findings, published in the journal Current Biology, reveal that when fully grown, a North Atlantic right whale born today would be expected to be about one meter shorter than a whale born in 1980. Currently, full-grown members of the species average 13 to 14 meters in length.

Researchers used high-resolution photographs to ’track size and body condition of 129 right whales. Their research indicated that a major reason for the animals’ recent growth problem is entanglement (缠绕) in rope and fishing equipment.

North Atlantic right whales typically move up and down the Eastern seaboard, from Florida to Canada. In recent years, more than half the population can be found from late winter to early spring off the coast of Cape Cod, where they sail through a deadly maze (迷宫) of rope and fishing equipment.

Entanglements in the equipment can lead to life-threatening infections, starvation, or drowning (溺水). Even when they don’t kill the whales, they can cause long-term harm, the researchers found. When the whales get caught in fishing equipment and end up dragging it around, it forces them to expend more energy fighting to survive, instead of growing or reproducing. Not only does entanglement contribute to reduced body size for an individual whale, but female North Atlantic right whales entangled while nursing produce smaller babies. That threatens the repopulation of a species with so few remaining members.

In response, conservationists say managers of fishing grounds need to better manage the fishing grounds, whose equipment on the seafloor is considered the primary cause of entanglements. One potential answer is greater investment in the development and testing of ropeless fishing technology.

“There is no time to wait,” researchers said. “The species can’t tolerate any further impacts, or it will have no future.”

There were four friends named Tom, Jack, John and Tony. They lived in the same village. Once, they were invited to attend a marriage party in a distant village, and they decided to go there together.

They started early that morning so that they could go through the forest before darkness. While they were going through the forest cautiously, they could not enjoy its beauty because they were afraid of wild animals. That's why they wanted to go through the forest quickly.

By noon, they had gone through more than half the way. All of a sudden, Tom asked the rest to stop and said, "The area ahead is dangerous, for there may be tigers. Let us check first, and then we will go further." They all looked here and there. Suddenly, Tony saw the tail of a tiger behind the bushes. He was frightened and cried, "There is a tiger behind the bushes! Now, what do we do? How can we save our lives?" Tom said, "Do not be afraid of the tiger. Believe in God. He will protect us."

Jack climbed up a tree and said to his friends, "Do not waste time in talking. Quickly! Climb up a tree. God helps those who help themselves. Be quick! Save yourself." So Tom, John and Tony rushed to a nearby tree and climbed up. When the tiger went away, they came down from the tree. Finally, they went through the forest safely and reached the village to attend the marriage party.

Crows are not the most beautiful bird. They don't have a good fame in most countries of the world. 【小题1】 They are definitely one of the smartest, most adaptable of our winged friends.

【小题2】 However, some of these species may also have small areas of white or gray feather around their body. And they are compact（结实的）birds with functional beaks and feet.

Crows are very socialized to groups These groups of crows are referral to as "flocks" or "murder". The American crow, also known as the common crow, is of the Corvidae family. This includes 120 species. 【小题3】

In a variety of studies crows have been proven to be extremely intelligent. These studies confirm that the birds are able to construct and use tools in their life. 【小题4】 Crows have actually evolved into making hooked tools from twigs to help them forage. They are also able to drop pebbles into a lube of water to allow them to drink the water.

【小题5】 And they also stash and store food in trees and other places for future use. They are highly adaptive birds that eat over six hundred different kinds of stuff. They eat almost all types of plants. And they also feed on insects like spiders, grasshoppers, weevils, beetles and crickets. As scavengers（食腐动物）they feed on decaying and dead matter. And also eat waste and food from garbage biw, especially in the winter months.