[填空题]There are two types of headache: one is ______; the other is the unfamiliar type.

[填空题]There are two types of headache: one is ______; the other is the unfamiliar type.

[简答题]loon birds have two types of feather to protect them in the cold water, they are water birds live in cold climate in north America, 1st, counterfeit (不确定), feather which is the outer layer of the birds’ body. This type of feather keeps the birds dry, it is packed tightly and olily wich keep the water going into the body. 2nd type, is down feather, wich keeps the bird warm. It is dense and thick and is make of soft fluffy material. So it prevents the heat loosing for the body

[单项选择]
One of the most basic elements of human life is the way in which we form social groups and interact with the members of those groups. According to sociologists, no one is ever entirely separate from the social networks that surround him or her, and the groups we belong to play an enormous role in determining how we see ourselves and our world. Early American sociologist Charles H. Cooley (1864～1929) defined two principal categories of human groupings, and his ideas are still widely accepted today. He termed them primary and secondary, based on the kinds of relationships individuals in the group share with each other.
In primary groups, we form what Cooley referred to as primary relationships. These are marked by strong, long-lasting emotional ties, feelings of intimacy and genuine concern for the well-being of the other person or people. Intangible items, such as love, respect, and support, are exchanged by
A. By using definitions formulated by earlier American sociologists.
B. By focusing on the types of interactions displayed by group members.
C. By assigning values to groups based on their role in personal development.
D. By comparing the types of roles they play in society.

[填空题]There are two main types of elephants. There is the Asiatic elephant, which is found in India, for example, and the African elephant. Superficially they are very much alike, but the African elephant is generally larger. One characteristic of Asiatic elephants is that they do not like being exposed to the sun, and consequently they prefer to live in shady places. They ale also very fond of bathing.
Apart from that, the most important difference between the two types of elephants is that the Asiatic elephant is more easily trained. Elephants in India, for example, have been caught and tamed for many hundreds of years. We have already noted that they have good memories, and it is this that makes them easy to train. Since they are immensely strong, they can can-y and drag huge objects, such as the trunks of trees, and rocks. This makes them extremely valuable as beasts of burden.
Two main types of elephants: (1) , and (2) .
Asiatic elephants do not