Read the following paragraph and write the topic sentence on the answer sheet. 　Incidentally the word astronomy(天文学）comes from the Greek word astron, which means star. Actually, there are many interesting origins of words that are linked to the stars or planets. The word disaster, for example, comes from the Latin dis-aster meaning bad star. We sometimes call a crazy or strange person a lunatic(疯子)，which is from the word lunar meaning moon一it was believed that the moon could make some people crazy, especially a full moon. Finally, the word influenza, or flu, comes from the Latin influenza. It was believed the illness was caused by unfavorable star influences. And of course we call famous singers or film actors stars in recognition of the lucky stars that have brought them fame and fortune.