Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the best answer to each of the following questions from 23 to 30.
There are an estimated 3 billion American crows living in North America. Though they are often confused with their cousin, the raven, crows are smaller and more common. Once found only in rural areas, they now live just about everywhere. Their ability to live alongside humans has allowed them to thrive.
At night, crows may gather in huge flocks of a few thousand to roost in trees. The largest flock had an estimated 200,000 birds! Their ear-splitting calls of "caw, caw" fill the air. At dawn, the birds separate to search for food and return to roost at the end of the day. Their diet includes plants, animals, and handouts from humans. Crows will crack open shellfish by dropping them on rocks, search cornfields for anything the farmer left behind, and explore people's backyards for insects, frogs, and eggs. Groups of crows will often roost in the same spot for several winters.
They are believed to mate for life, and both the male and the female share the task of nest-building. When the young hatch and leave the nest, they do not set out on their own. Instead, the family sticks together.
Research has proven the American crow to be among the most intelligent of birds. They can count up to three or four, solve puzzles, retain information, and recognize symbols. In fact, these abilities have probably contributed to the Crow's reputation as a clever pest which will often outwit human attempts to keep “them” away. More and more people, however, are recognizing potential benefits of these omnivorous birds which eat many kinds of harmful insects and chase away predators like hawks and owls.
