关于梁板式肋形楼盖叙述正确的是( )。 A．板支撑在次梁上沿短边方向传力 B．次梁

Can dolphins talk ? Maybe they can’t talk with words ,but they can talk with sounds . They show their feelings with sounds .

Dolphins travel in group . We call a group of them a “school “. They don’t study , but they travel together.

Dolphins talk to other dolphins in the school .They give information . They tell other dolphins when they are happy or sad or afraid . They say “welcome “when a dolphin comes back to the school . They talk when they play .

They make a few sounds above water . They make many more sounds under water . People can hear these sounds because they are very high .

Sometimes people catch dolphins for large aquariums . People can watch the dolphins in a show . Dolphins don’t like to be in the aquarium , being away from their school . They are sad and lonely if they do so .

There are many stories about dolphins . They help people . Sometimes they save someone’s life . Many people believe that dolphins can bring good luck .

小题1:Dolphins show their feelings with ________.

A．pictures

B．words

C．waves

D．sounds小题2:Dolphins __________ in the school according to the passage.

A． give information

B．don’t tell other dolphins when they are afraid

C． talk when they sleep

D．say “ sorry” when a dolphin comes back小题3:People can’t hear the dolphin’s sounds because ______________>

A．they are above the water

B．they are under the water

C．they are very high

D．they are very low小题4:Many people believe that dolphins can bring_______________.

A．good luck

B．health

C．wealth

D．danger小题5:Which of the following is TRUE ?

A． Dolphins study in the school.

B．Dolphins travel in a group.

C．Dolphins like to be away from their school.

D．Dolphins sometimes kill people.

“五一”这一天（　　）

A．北京昼夜等长

B．中国南极长城站（62°S，57°W）没有黑夜

C．悉尼（151°E，33°S）昼长夜短

D．伦敦（0°，51°N）昼长夜短

指出肺痈“口啖生豆不腥”的医著是

A．《医学入门》

B．《医灯续焰》

C．《张氏医通》

D．《红炉点雪》

E．《医碥》

下列关于网络拓扑结构的叙述中，正确的是

A．网络拓扑结构是指网络结点间的分布形式

B．目前局域网中最普遍采用的拓扑结构是总线结构

C．树型结构的线路复杂，网络管理也比较困难

D．树型结构的缺点是，当需要增加新的工作站时成本较高

简述什么叫层间水？