问题 问答题

何谓误差复映

答案

参考答案:由于毛坯加工余量和材料硬度的变化,引起切削力和工艺系统受力变形的变化,使毛坯的误差反映到加工后的工件表面,这种现象称为“误差复映”。

单项选择题
阅读理解

阅读理解。

     With the Tesla Roadster and other plugin (插入式) electric vehicles hitting the road, demand is

growing for accessible refueling points to recharge them. Carbon Day Automotive,a Chicagobased

company,has now demonstrated a solarpowered recharging point,known as the Solar PlugIn Station,

which lets motorists easily charge their cars using electricity that has been produced without any

environmental damage.

     The Solar PlugIn Station has gone on show in Chicago as part of the city's bid to host the 2016

Olympic Games. According to Carbon Day Automotive,the Solar PlugIn Station on show in Chicago

is part of the vital infrastructure (基础设施) required for electric vehicles in Chicago and was the focus

of a recent visit by the International Olympic Committee.

     These solarpowered electricity points will be used daily to fuel the city's electric vehicles with power

from the sun. By producing the electricity from pollutionfree solar cell,the CO2 emissions are reduced to

zero.

"Solar energy and electric vehicles are a partnership that is one more step to reducing our dependence

on foreign oil," says Richard Lowenthal,CEO of Coulomb Technologies. Coulomb Technologies recently

developed the components (部件) required for individual recharging stations,marketed as ChargePoint

Networked Charging Stations. Carbon Day Automotive is the Midwest distributor for the ChargePoint

stations.

     The Solar PlugIn Station consists of giant solar panels (电池板) that shade the tiny ChargePoint

Networked Charging Station. The solar panel is connected to an underground battery pack,ready for

everyday refueling.

     "Without these stations it would be like driving around in a traditional car without the availability of

gas stations," says Scott Emalfarb,CEO at Carbon Day."The day of true plugin electric vehicles will be

here sooner than most people realize and the world needs to be ready to accommodate them."

1. The Solar PlugIn Station is used as part of the bid to host the Olympics mainly because ______.

A. it's environmentally friendly

B. it makes up for the lack of electricity

C. it's a new idea and attracts people's attention

D. it brings convenience to electric vehicle users

2. The passage implies that when the Solar PlugIn Station becomes popular,________.

A. more visitors will come to Chicago

B. more space for electric vehicles will be needed

C. the citizens of Chicago will be able to go to work faster

D. the cost of electric vehicles will be lower than traditional cars

3. What would be the best title for the passage?

A. Chicago Will Soon Be Full of Electric Vehicles

B. Chicago Calls on People to Buy Electric Vehicles

C. Chicago Fights for Its Bid to Host the 2016 Olympics

D. Chicago Shows Its Solarpowered Recharging Stations