单项选择题：空间曲线在xOy平面的投影方程是（）。 A. B. C.x+2y2=16 D.

题型：单项选择题

William H. Gates is chairperson and chief software architect of Microsoft Corporation．the worldwide leader in software services and internet technologies for personal and business computing．

Bill Gates was born on October 28．1 955 in a family having rich business，political and community service background．His great—grandfather was a state legislator(立法者)and a mayor，his grandfather was vice president of national bank and his father was a lawyer．

Bill strongly believes in hard work. He believes that if you are intelligent and know how to apply your intelligence，you can achieve anything．From childhood Bill was ambitious, intelligent and competitive．These qualities helped him to attain top position in the profession he chose．1n school，he had an excellent record in mathematics and science．Bill’s parents came to know their son’s intelligence and decided to send him to a private school，known for its good academic environment．It was a very important decision in Bill Gates’ life where he was first introduced to a computer．Bill Gates and his friends were very much interested in computer and formed “programmer’s Group” in late l968．

Later，Bill Gates and his close friend Allen started a new company of their own，Traf-O-Data．They developed a small computer to measure traffic flow．From this project they earned around$20，000．In 1973．he left home for Harvard University．He did well over there，but he couldn’t find it interesting．He spent many long nights in front of the school’s computer and the next day asleep in class．

Within a year．Bill Gates dropped out from Harvard．Then he formed Microsoft．Microsoft’s vision is“ A computer on every desk and Microsoft software on every computer”．His belief in high intelligence and hard work has put him where he is today．He does not believe in mere(纯粹的)luck，but just hard work and competitiveness．

Bill Gates is not a greedy person．In fact，he is quite a giving person when it comes to computers，internet and any kind of funding．Several years ago, he visited Chicago’s Einstein Elementary School and announced grants benefiting Chicago’s schools and museums where he donated(捐款)a total of $1 1 0，000，a bunch of computers，and provided internet connectivity to a number of schools．Secondly，Bill Gates donated 38 million dollars for the building of a computer institute at Stanford University．Gates has decided to give away 95％of all his earnings when he retires．

小题1:．How old was Bill Gates when he retired from Microsoft in late June of 2008?