问题 选择题
某交流电电源电压的瞬时值表达式为u=6sinl00πt(V),则下列说法中正确的是(  )

A.用交流电压表测该电源电压时,示数是6V

B.用交流电压表测该电源电压时,示数是6V

C.用此电源给电磁打点计时器供电时,打点的时间间隔为0.01s

D.把标有“6V 3W”的小灯泡接在该电源上时,小灯泡将被烧毁

答案

答案:A

阅读理解

Have you got some paper, a pair of scissors and, above all, a desire to decorate your house? Then, we have the perfect holiday artwork for you: Make Star Wars snowflakes (雪花). Remembered as a cherished form of work in classrooms before the holidays, paper snowflakes have drawn many people's attention again.

The designer, Anthony Herrera, just recently released his 2013 collection. "The Star Wars snowflake designs began as just doing designs of characters that I and my daughter wanted to make three years ago," Herrera told us in an email. "The second year I introduced vehicles, and this year I decided to push further by designing battle scenes."

Sometimes, he feels a bit bored with his job. With each year, the designs have got more detailed and various, but the process of creating them remained the same: sketching figures on paper with a pencil until a symmetrical (对称)pattern comes out, then scanning the designs and cut them with scissors. However, he says he has plenty of ideas for new flakes next year, so no two will ever be the same. Hopefully with Star Wars: Episode VII coming in 2015 he'll have even more work in the future.

Check out your favorite finished versions of Herrera’s flakes (from both 2013 and previous years) and download the pictures beneath them and then get down to creating your own work. A warning: Most designs aren't for the casual flake-maker, so patience you must have.

小题1: Making paper snowflakes draws many people's attention probably because ______.

A.it is a traditional form of decoration

B.it is a course of artwork in school

C.it is a way of killing time in holiday

D.it is designed by Anthony Herrera小题2: From the text, we know that Herrera ______.

A.can make snowflakes with his daughter's help

B.made more complicated designs before 2013

C.introduced paper vehicles in 2011

D.will make a great variety of detailed paper flakes小题3: Herrera is fed up with the job sometimes because ______

A.he has to design detailed and different patterns

B.he has to follow the fixed process of paper cutting

C.he spends much time designing, scanning and cutting

D.he has few ideas for what the next designs will be like小题4: By writing the last paragraph, the author tries to ______.

A.offer us more information about Herrera’s paper cutting

B.tell us how to download picture of snowflakes

C.instruct people to be a real creative artist

D.remind us of being patient with Herrera’s designs

单项选择题