---I don’t know how to write the article assigned by our professor on international trade.
--You should have ______ your attention on the lecture that ______ how international situation affects exports and imports across the globe.
| A．put; concentrate on | B．paid; talked about |
| C．fixed; dealt on | D．focused; focused on |
We _________ some money every month in order to buy a computer.
| A．set out | B．set up | C．set aside | D．set about |
I soon found that the work I was doing had already been done by someone else. _______, I was wasting my time.
| A．In other words | B．In a word | C．As a result | D．In addition |
Many friends sent me e-mail to ________ me on the birth of my son.
| A．celebrate | B．reward | C．express | D．congratulate |
Many people ________ the accident, so it was not difficult to investigate（调查）.
| A．witnessed | B．yelled | C．annoyed | D．envied |
It was along the Mississippi River _________ Mark Twain spent much of his childhood.
| A．how | B．which | C．that | D．where |