【简答题】A person steps on what seems like solid ground but discovers with horror that the ground is giving way underfoot. The person struggles desperately but is trapped. There is no escape. Slowly the person...
【单选题】听力原文: A ground hog is a small animal that digs and lives under the ground. It is also called the woodchuck. Ground hogs live in many parts of America. In the winter they sleep like beam and some other...