What have you learned since you came here? How many new friends have you made already? I hope you have met already a lot of interesting people.

Since classes began I have not hadmuch free time. I have had several big tests to study for.

Last night my roommate and I have had some free time, so we went to a show.

I admit that I got older since I last have seen you, but with any luck at all, I also got wiser.

Since the beginning of the twentieth century, medical scientists have mademany important discoveries.

Libraries today are diffrent from those in 1800s. For example, the contents of libraries have changed greatly through the year. In the 1800s, libraries were simply collections of books. However, today most libraries have becomemultimedia centera that contain tapes.