如图是牙齿的结构模式图．请据图回答： （1）人体结构中最坚硬的部分是[_____

男性，24岁，不慎跌入80℃热水池内，池水淹没下半身超过臀部，初步估计烫伤面积为()

A.30％～34％

B.35％～39％

C.40％～44％

D.45％～50％

E.>60％

尽管通胀预期与现实的通胀还不是一回事，它通过不断积累可以促使通胀发生，而且通胀预期带来的行为将加剧通胀的压力。如果不加以正确管理、引导和化解的话，它都可能被积累放大，形成通胀恐慌，最终导致通胀“实现”。 根据这段文字，“通胀预期”与“通胀”的关系是( )。

A．通胀预期将最终导致通胀

B．通胀预期可能导致通胀

C．通胀预期是通胀的前奏

D．通胀预期带来的行为将加剧通胀

不能采用免疫透射比浊法测定的蛋白质是（）

A.铜蓝蛋白

B.前清蛋白

C.IgG

D.AAT

E.黏蛋白

沥青路面养护有那些指标？（）

A、破损率

B、强度

C、平整度

D、抗滑能力

Scholars of human migration speak of two main factors that influence an individual’s decision to move from one place to another-push and pull factors. Push factors are associated with the place of origin. A push factor can be as simple and mild a matter as difficulty in finding a suitable job, or as traumatic as religious persecution, war, or severe famine Obviously, refugees who leave their homes with guns pointed at their heads or with hate-filled mobs at their heels are motivated almost entirely by push factors (although pull factors do influence their choice of destination).

Pull factors are those associated with the place of destination. Most of these are economic, such as better job opportunities or the availability of good land to farm. The latter was an important factor in attracting settlers to the United States during the nineteenth century. In general, pull factors add up to an apparently better chance for a good life and material well-being than is offered by the place of origin.

Besides push and pull factors, there are what the sociologists call " intervening obstacles " . Even if push and/or pull factors are very p, they still may be outweighed by intervening obstacles, such as the distance of the move, the trouble and cost of moving, the difficulty of entering the new country, and the problems likely to be encountered on arrival.

The decision to move is also influenced by " personal factors " of the potential migrant. The same push-pull factors and obstacles operate differently on different people, sometimes because they are at different stages of their lives, or just because of their varied abilities and personalities. The prospect of pulling up stakes and moving to a new and perhaps very strange environment may appear interesting and challenging to a young, footloose man and appallingly difficult to a slightly older man with a wife and young children. Similarly, the need to learn a new language and customs may intrigue one person and frighten another.

Regardless of why people move, migration of large numbers of people causes friction. The United States and other " receiving countries " (the term used for countries that welcome large numbers of migrants) have experienced adjustment problems with each new wave of immigrants. The newest arrivals are usually given the lowest-paying jobs and are resented by natives who may have to compete with them for those jobs. It has usually taken several decades for each group to gain acceptance in the mainstream of society in the receiving country.

Refugees migrate out of their country probably because of（）

A. their country’s unstable situation

B. bad economic conditions

C. guns pointing at them

D. their resentment towards government