Mark Twain worked for several years as a pilot on a steamboat, taking passengers up anddown the Mississippi, the great river ___flows from the north of the US near the Canadianborder.

It is impossible for us to carry the stone statues, all of______ are too heavy.

 This book is written by my sister, _________ is working for CCTV.

Is this the reason ______ at the meeting for his carelessness in his work?

Mr. Mike, in ______ supermarket we bought an ipad last week, will give us a report on management this evening.