用循环语句描述1+$\frac{1}{2}$+$\frac{1}{2^2}$+$\frac{1}{2^3}$+…+$\frac{1}{2^9}$．

    Never Put off Tomorrow What You Can Do Today

    Want to put off studying for the physics test? Or writing that thirty-five-page research paper on future uses of biotechnology? Sure you do? And who wouldn't? But it's still a silly idea to put off doing something until a future time. Here is why ....

    ____. The task will be still the same. It won't be any more fun and you still won't want to do it. As the deadline gets closer and closer, the task seems to become larger and larger if you haven't started the work. And the stress increases. Now not only do you have to write that paper, you have to do it under great pressure.

    ____ . Before you start, it seems that the task is unlikely to be accomplished. But you know what? You're probably miscalculating. Get started -------- maybe on a small piece ------ And you will discover that you have more resources and know more about the subject than you thought. Result? You won't experience nearly as much suffering as you expected to. Things are guaranteed ------ 100 percent ------- to get better.

    ____ . If you leave your work before the night before it's due, you give up the possibility of getting input from your professor. Professors regularly give advice ----- or at least a few useful tips ---- during office hours. Unfortunately though, they don't usually hold office hours at midnight, so you will be out of luck when you discover the night before the midterm that you have no idea how to do the questions that will count for two-thirds of your grade.

    ____ Ever wonder why the professor assigns the papers two weeks before it's due? It's because he or she expects you to be thinking about the issue, or doing the research, for two weeks. No, not every waking moment, but at least some of the time. After all, the professor could just as easily have given the assignment one week before it was due if he or she expected less thinking. When you throw together a paper or a report at the last minute, your ideas are half-baked. And your professor will know it.

    ____ . If you put things off at the last minute, you might find that you haven't budgeted enough minutes to finish the necessary tasks. It's the easiest thing in the world to miscalculate how long it will take to do all the work especially when new issues arise ------ like illness, family problems, computer breakdowns, trouble at work, and all the other things ------- as you are thinking through your paper argument or preparing yourself for the coming test. If you keep delaying, you don't allow yourself time for those various life events that have an adverse(不利的) effect on your ability to complete your assignment.