A、They cost a lot of money. B、They scatter their investment C、They often risk investing in unsure projects. D、They are not good

[20]It is well that young men should begin at the beginning and occupy the most subordinate positions. Many of the leading businessmen had a serious responsibility thrust upon them at the very beginning of their career. They were introduced to the broom, and spent the first hours of their business lives sweeping out the office. I notice we have cleaners now in offices, and our young men unfortunately miss that beneficial branch of business education. But if by chance the professional sweeper is absent any morning, the boy who has the genius of the future partner will not hesitate to try his hand at the broom. It does not hurt the newest comer to sweep out the office if necessary. I was one of those sweepers myself.
    [21]Assuming that you have all obtained employment, my advice to you is "aim high". I would take the young man lightly who does not already see himself the partner or the head of an important firm. Do not rest content for a moment in your thoughts as head clerk, or general manager in any concern, no matter how extensive. Say to yourself, "My place is at the top." Be king in your dreams.
    And here is the prime condition of success, the great secret concentrate your energy, thought, and capital exclusively upon the business in which you are engaged. Having begun in one line, resolve to fight it out on that line, to lead in it, adopt every improvement, have the best machinery, and know the most about it.
    [22]The unsuccessful companies are those which have scattered their capital, which means that they have scattered their brains also. They have investments in this, or that, or the other and everywhere. "Don’t put all your eggs in one basket." is all wrong. I tell you to "put all your eggs in one basket, and then watch that basket." Look round you and take notice, men who do that not often fail. It is easy to watch and carry the one basket. It is trying to carry too many baskets that breaks most eggs in this country. He who carries three baskets must put one on his head, which is apt to tumble and trip him up. One fault of the American businessman is lack of concentration.
    To summarize what I have said: aim for the highest; never enter a bar room; make the firm’s interest yours; break orders always to save owners; concentrate; put all your eggs in one basket, and watch that basket; lastly, be patient, for as Emerson says, "no one can cheat you out of ultimate success but yourselves."
20. What do we learn about sweeping out the office according to the speaker?
21. What is the speaker’s advice for new employees?
22. According to the speaker, why did some companies fail?