--What do you think of Lady Gaga?--Maybe she is one of ________ singers in the world.
Math is not easy, I like it very much.
My parents are so poor that they can not to send me to school.
—I lost my watch on my way to school this morning. —You must be careful next time.
Xi’an is ancient county with long history.
I am not hungry because I have ____ had lunch.