题目内容
We know that many animals do not stay in one place. Birds, fish and other animals move from one place to another at a certain time. They move for different reasons; most of them move to find food more easily, but others move get away form places that are too corwded.When cold weather comes, many birds move to warmer places to find food. Some fishes give birth in warm water and move to cold water to feed. The most famous migration(迁移) is probably the migration of the fish, which is called “salmon”. This fish is born in fresh water but it travels many miles to salt water. Then it gives birth and dies there. In northern Europe, there is a kind of mouse. They leave their mountain homes when they become too crowded. They move down to the low land. Sometimes they move all the way to the seaside, and many of them are killed when they fall into the sea.Recently, scientists have studied the migration of a kind of lobster(龙虾). Every year, when the season of bad weather arrives, the lobsters get into a long line and start to walk across the floor of the ocean. Nobody knows why they do this, and nobody knows where they go .So, sometimes we know why humans and animals move from one place to another, but at other times we don’t. Maybe living things just like to travel. The passage is mainly about ()
查看答案
搜索结果不匹配？点我反馈
更多问题
The flying fox is not a fox at all. It is an extra large bat that has got a fox’s head, and that feeds on fruit instead of insects. Like all bats, flying foxes hang themselves by their toes when it rest, and travel in great crowds when out flying. A group will live in one spot for years. Some- times several hundreds of them occupy(占据) a single tree. As they return to the tree toward sunrise, they quarrel among themselves and fight for the best places until long after daylight.Flying foxes have babies once a year, giving birth to only one at a time. At first the mother has to carry the baby On her breast wherever she goes. Later she leaves it hanging up, and brings back food for it to eat. Sometimes a baby falls down to the ground and squeaks((尖叫) for help. Then the older ones swoop (俯冲) down and try to pick it Up. If they fail to do so, it will die. Often hundreds of dead baby bats can be found lying on the ground at the foot of a tree. Flying foxes tend to()
Many teachers believe that the responsibilities for learning lie with the student. (61) a long reading assignment is given, instructors expect students to be familiar with the (62) in the reading even if they do not discuss it in class or take an examination. The (63) student is considered to be (64) who is motivated (激发) to learn for the sake of (65) , not the one interested only in getting high grades. Sometimes homework is returned (66) brief written comments but without a grade. Even if a grade is not given, the students is (67) for learning the material assigned. When research is (68) , the professor expects the student to take it actively and to complete it with (69) guidance. It is the (70) responsibility to find books, magazines, and articles in the library. Professors do not have the time to explain (71) a university library works; they expect students, (72) graduate students, to be able to exhaust the reference (73) in the library. Professors will help students who need it, but (74) that their students not be (75) dependent on them. In the United States, professors have many other duties (76) teaching, such as administrative or research work. (77) the time that a professor can spend with a student outside of class is (78) . If a student has problems with classroom work, the student should either (79) a professor during office hours (80) make an appointment. 61()
Section B He has so many inventions that he is really______ Edison of ______Japan.()
分析楚汉战争中刘、项胜负的原因。
微信支付 
支付宝支付