简述数据库系统的特点。

以下CT表现中，对真菌性鼻窦炎具有定性诊断价值的是（）

A.窦腔内软组织密度影

B.窦壁骨质结构完整

C.双侧下鼻甲肥大

D.窦壁黏膜增厚

E.窦壁软组织密度影伴有斑点或斑块状钙化

原发性肝癌单纯型（）。

A.有或无肝硬化表现，有持续性发热及谷丙转氨酶增高

B.有肝硬化表现，肝功能改变符合肝硬化

C.无肝硬化的表现，肝功能试验基本正常

D.颈静脉充盈，肝大，肝颈静脉回流征阳性

E.迅速肿大的压痛性肿块，突然出现腹膜刺激征

化学知识中有很多的“相等”，请你判断下列说法中不正确的是[ ]

A．溶液稀释前后，溶质的质量相等

B．化合物中元素化合价的正价总数与负价总数的数值相等

C．50mL的水和50mL的酒精混合后，所得溶液的体积等于100mL

D．物质发生化学变化前后，质量总和一定相等

Psychologists tell us that there are four basic stages that human beings pass through when they enter and live in a new culture．This process begins with the “honeymoon stage”．This is the period of time when we first arrive in which everything about the new culture is strange and exciting．We may be suffering from “jet lag” but we are thrilled to be in the new environment, seeing new sights, hearing new sounds and language, eating new kinds of food．This stage can last for quite a long time because we feel we are involved in some kind of great adventure．

Unfortunately, the second stage can be more difficult．After we have settled down into our new life, we can become very tired and begin to miss our homeland and our family, friends, pets．All the little problems in life seem to be much bigger and more disturbing when you face them in a foreign culture．This period of cultural adjustment can be very difficult and lead to rejecting or pulling away from the new culture．

The third stage is called the “adjustment stage”．This is when you begin to realize that things are not so bad in the host culture．Your sense of humour usually becomes stronger and you realize that you are becoming stronger by learning to take care of yourself in the new place．Things are still difficult, but you are now a survivor!

The fourth stage can be called “at ease at last”．Now you feel quite comfortable in your new surroundings．You can cope（deal） with most problems that occur．You may still have problems with the language, but you know you are strong enough to deal with them．

小题1:This passage mainly talks about ________．

A．culture and foreign language learning

B．adventures in a foreign land

C．getting used to a new culture

D．the interaction of different cultures小题2:Which of the following best describes the first stage?

A．Lonely and depressed

B．Bored and homesick

C．Happy and excited

D．Angry and frustrated小题3:According to the passage, people are most likely to return to their own culture at the ________stage．

A．1st

B．2nd

C．third

D．fourth小题4:It can be concluded from the passage that ________．

A．people feel better in their own culture

B．it is not easy to adapt to a new culture

C．culture shock doesn’t occur at the beginning

D．it is human nature to long for adventures

患者男性，16岁，1小时前牙外伤求诊。检查：冠1／3折未露髓，折断面敏感，叩诊（+），冷测一过性敏感

医生让患者去做X线片检查，目的是确定（）。

A.髓腔大小

B.牙根长度

C.有无根折

D.牙周情况

E.根尖发育