21．I remember doing the household chores to help my mother when I was nine．I hated changing the vacuum cleaner（真空吸塵器）bag and picking up things the machine did not suck up．Twenty years later，in 1978，with this lifelong dislike of the way the machine worked，I decided to make a bagless one．
Easier said than done，of course．I didn't realize that I would spend the next five years perfecting my design，a process that resulted in 5，127 different prototypes（樣機(jī)）．By the time I made my 15th prototype，my third child was born．By 2，627，my wife and I were really counting our pennies．By 3，727，my wife was giving art lessons for some extra cash，and we were getting further and further into debt．These were tough times，but each failure brought me closer to solving the problem．
In the early 1980s，I started trying to get licensing agreements for my technology．The reality was very different，however．The major vacuum makers had built a business model based on the profits from bags and filters（濾網(wǎng)）．No one would license my idea，not because it was a bad one，but because it was bad for business．But soon after，the companies that I had talked with started making machines like mine．I had to fight legal battles on both sides of the Atlantic to protect the patents on my vacuum cleaner．
I was still in financial difficulties until 1993，when my bank manager personally persuaded Lloyds Bank to lend me ＄1 million．Then I was able to go into production．Within two years，the Dyson vacuum cleaner became a best-seller in Britain．
Today，
I still embrace risk and the potential for failur as part of the process．Nothing beats the excitement of invention．
（1）What drove the author to make a bagless vacuum cleaner？ （No more than 10 words）
（2）What does paragraph 2 mainly tell us？ （No more than 10 words）
（3）Why did the companies refuse to license the author's technology？ （No more than 10 words）
（4）What does the underlined sentence in the last paragraph mean？ （No more than 10 words）
（5）What lesson may you learn from the author's experience？ （No more than 25 words）
