【单选题】Little guys, who do not have plenty of money but have great interest in space tourism, are trying to make the space travel less expensive but more reliable.
【简答题】Going to the beach is many American’s favorite activity. They went swimming in the ocean without giving a thought to what was underwater. But those days are long gone. In the summer of 1988, many of t...
【单选题】-Hey, guys. Do you often have a good time ________ after-school activities? -Of course, we do. And we always have a lot of time ________ soccer. [ ]