From 1992 until his election to the U.S. Senate in 2004, Barack Obama served as a professor in the Law School. He was a Lecturer from 1992 to 1996. He was a Senior Lecturer from 1996 to 2004, during which time he taught three courses per year.
Traditional speakers produce sound by using an electromagnet to move a flexible cone back and forth. They use drivers to help translate electrical signals into physical vibrations so that you can hear recorded sounds. A tweeter is the type of speaker driver that produces the highest range frequency. The other two main drivers are woofers and midrange. Basically, a driver moves a flexible cone, or diaphragm, back and forth very quickly to produce sound waves.
General vs @Tweets. 1  There's a distinction between general tweets & tweets directed at a particular person (@tweets OR @replies if your responding to someone). 2  A general tweet is one you just type and that all your followers will see. 3  Anyone doing a search for any keyword in that tweet will also see it.ifferent types of conversationsâ¦ and who sees them. A general default tweet: this is a statement or conversation that everyone can hear. @tweet (or @reply if you responding to a tweet) : Imagine this as addressing one person in a group conversation.