We all need knowledge from the past — ______ it comes from personal experience or from studying history. It is our only guide to the future.
It was a really ___________ experience. Afterwards everybody was very ___________.
With so much noise of the traffic,I couldn’t________ my research work.
Word came _________the first patient who had been infected with A(H1N1) flu was cured.
—Everybody knows smoking is harmful to health,but still so many people smoke. —Exactly! So our country is planning to start a ________ against smoking.
There are so many tall trees in the forest, ______ .