All flights __________ because of the snowstorm, we decided to take the train.
| A．were canceled | B．had been canceled |
| C．having canceled | D．having been canceled |
. Statistics ________ that most of the published and quoted scientific articles are related to medical science.
| A．has shown | B．is shown | C．show | D．shows |
. Times ________ hard but the New York Times still ________ a wide circulation.
| A．are; has | B．are; have | C．is; has | D．is; have |
. Two hundred dollars ________ a small price to pay for the secondhand refrigerator.
| A．have been | B．has been | C．are | D．is |
. Many a man ________ swimming in the river, but only ________ can swim across it.
| A．go… a few | B．goes… a few | C．go… few | D．goes… Few |
. Man, just like lower forms of life, ________ the product of the evolutionary process.
| A．are | B．is | C．had been | D．were |