In the search for clean． renewable（可再生的） energy． wind power might be the perfect choice．People have been using the power of the wind for centuries．Since ancient times， wind power has been used to move ships， grind （碾谷）and so on，Around the end of the 19 ^thcentury， the invention of the wind turbine（涡轮机） made it possible to use Wind to produce electricity．

The first advantage of wind power is that it is a renewable resource{能源）． No mater how much wind we use to produce electricity， it will never run out． Secondly， wind power i a clean resource of enery， meaning it produces electricity without harmful emissions（排 放物）． Thirdly，although wind turbines can be very tall， each uses only a small piece of land． This means that the Land below can still be used．

Yet． wind energy has some disadvantages．One of the disadvantages is that the large spinning lodes（螺旋桨叶） of the wind turbines can be dangerous to birds． The second is that the turbines create noise pollution． The sound may make the people nearby uncomfortable． The third，wind can not provide a constantsupply（供应） of energy． Even the windiest places on Earth are peaceful． Without a strong wind， wind turbines are not able to produce electricity． That means wind power isn't suitable as the only resource of electricity．

Although wind energy has certain disadvantages， there is no reason why we should give up this renewable and clean resource of energy． Wind energy certainly is one of the bight hopes of our future．

（1）When did people start to use wind to produce electricity？ 　　

A．	Several centuries ago．
B．	At the beginning of the 19 ^thcentury．
C．	In the mid﹣19 ^thcentury．
D．	At the end of the 19 ^thcentury．

（2）How many advantages are mentioned in this passage？ 　　

A．	Two．
B．	Three．
C．	Five．
D．	Six．

（3）What's the main idea of the third paragraph（段）？ 　　

A．	The advantages of wind energy．
B．	The disadvantages of wind energy．
C．	The history of wind energy．
D．	The development of wind energy．

（4）The underlined word "constant" means 　　in Chinese．

A．	连续的
B．	短暂的
C．	无害的
D．	一次性的