下列金融工具中，其职能主要用于保值、投机的是( )。A．股票B．公司债券C．商业票

读图，回答问题。

小题1:若图中有一地位于南半球，这一地是  

A．甲地

B．乙地

C．丙地

D．丁地小题2:关于甲地的叙述，正确的是  

A．日落时刻为地方时18时

B．水平运动的物体向右偏转

C．一年中正午太阳高度角只有一次最大值

D．甲地的地球自转线速度小于丙地小题3:若甲地位于东八区的中央经线上，乙地位于东西半球分界线上，当甲地日出时，可能乙地的地方时是

A．4时40分

B．8时40分

C．16时40分

D．21时40分

实践是检验认识真理性的标准之一。

阅读理解

     London's River Thames has twenty-seven bridges.  But Tower Bridge,  the first bridge over the

Thames as you travel to London from the sea, is the most famous of them all.

     What makes Tower Bridge so exciting? Why do visitors come from all over the world to see it?

     The thing that is surprising about Tower Bridge is that it is open in the middle.  It does this to let

the big ships through to the pool (水域) of London.  If you are lucky enough to see the bridge with

its two opening arms high in the air, you will never forget it.

     On its north side stands the Tower of London itself.

     Although they look the same age, the Tower is almost a thousand years old, and Tower Bridge is

only about one hundred years old. It was built in 1890s. By 1850, everyone agreed that a bridge

across the Thames near the Tower was most necessary. But the designers argued (争 论) about the

bridge for another thirty years. This took so long because had two big problems.

1. Tower Bridge is____

A. about one thousand years old

B. the oldest and the most famous bridge in London

C. the first one you can see when you go from the sea to London

D. the one that took workers about 30 years to build

2. People in London agreed that___.

A. twenty-seven bridges should be built over Thames River

B. designers should argue about the bridge for about thirty years

C. a bridge should be built by people from all over the world

D. a new bridge should be built near the Tower of London

3. The Tower of London is___.

A. across the Thames

B. on the north of Tower of Bridge

C. in the middle of Tower Bridge

D. much younger than Tower Bridge

4.  From the reading we can learn that___.

A. you have to go from the sea Tower Bridge

B. the Tower of London doesn't look so old

C. Tower Bridge had two big problems

D. you can see Tower Bridge open its arms at any time

PDC主要以（）方式破碎岩石。

A.挤压

B.拉伸

C.扭转

D.切削

当起重机主要受力构件失去整体稳定时应修复，不应报废。（）