Before 1900, many theories existed as to the cause of yellow fever  . Some doctors were sure the disease was air-borne; others felt that it was spread from person to person. Dr. Carlos Finlay, a well-known Cuban doctor of that time, had long held the theory that it was caused by the bite of mosquitoes. But neither the public nor the doctors then accepted his idea.    Walter Reed,all American doctor sent to study yellow fever in Cuba,went to talk with Finlay.Reed,after reading a lot on the subject,had begun to think that Dr.Finlay might be fight.Then Reed and his comrades set to work at once.Outside Havana,they set up a laboratory and began experiments to test the theory.The experiments were successful.Now we know:A period of about two weeks must pass before a mosquito,after feeding on a sick person,could infect  another person.The sick person had to have yellow fever a certain number of days before the mosquito biting him was able to carry the disease. Reed proved the theory  _  . A) in his American lab B) by talking with Finlay C) in a kind of scientific Way D) by reading a lot of articles
C

Either out of confusion or discomfort we sometimes express our feelings in an unclear way. One key to making your feelings clear is to realize that you most often can shorten them in a few words: hurt, glad, confused, excited, angry, and so on. In the same way, with a little thought you can probably describe very briefly any reasons you have for feeling a certain way. In addition to avoiding too long expressions, a second way to prevent confusion is to avoid  _ your feelings by saying "I'm a little unhappy" or "I'm pretty excited". Of course, not all feelings are strong ones. We do feel degrees of sadness and joy, for example, but some communicators have a tendency to downplay almost every feeling. Do you? A third danger to avoid is expressing feelings in an indirect or coded manner. This happened most often when the sender is uncomfortable about showing his or her feeling in question. Some codes are verbal ones, as when the sender hints more or less subtly at the message. For example, an indirect way to say "I'm feeling lonely" might be "I guess there isn't much happening this weekend, so if you're not busy, why don't you drop by?" Such a message is so indirect that chances are small that your real feeling will be recognized. For this reason, people who send coded messages stand less of a chance of having their feeling understood and their need met. Finally, you can express yourself clearly by making sure that both you and your partner understand that your feeling is centered in a specific set of environments rather than being indicative of the whole relationship. Instead of saying "I hate you", say "I hate you when you don't keep your promises"'. Rather than "I'm bored with you", say "I'm bored when you talk about your money." From the beginning of the passage we sometimes express our feelings in an unclear way because   _  . A) we are in a very bad feeling B) we do not want to tell anyone about it C) we are not clear what it is D) we have just get rid of a discomfort
C

Many times  when  people  hear  the  words  social  networking,  their  brains automatically go to sites such as Twitter or Facebook.  However, there are sites for those into social networking and into reading.  Sound crazy?, It's really not. If you've ever wanted a site where you can receive book recommendations,follow your favorite authors,and keep up with what your friends are reading, then look no further than Goodreads. com. Goodreads provides useful services for those in the reading world.  It is a site where you can win books by going to giveaways and simply entering your information. Some giveaways are even signed by the author.   And the books aren't boring,old or torn copies ---- many of them are ARC's (Advanced Readers Copies),for which you can write a short review on the site.  Anyone can post reviews of their favorite books or series so that others may _ to read them as well. Another function of the site is offering book clubs and interest groups.  You can have interactive discussions with groups of people reading the same things,sort of like a blog.  You can also  make friends with people and post statuses similar to Facebook. Your friends can send you book recommendations and you can add them to your shelf if you choose. Shelves are by far one of the best features on the site.  You can categorize  your entire library and put books you want to read on your"to-read" shelf.  These virtual shelves allow you to see what you've read and also let you keep track of the number of books you've read in a year. You can even read original writing for free because many people post their own writing on the site to gain feedback and advice on how to improve. Anyone can join this site for free and fall in love with not just a book, but a book site as well. What do we know about the shelves on Goodreads. com? A) They are filled with all kinds of books from some libraries. B) The books there are categorized for readers by the site. C) That is where people put books they have read or want to read D) New books will continuously be added to readers by the site.

C