1 . 我心里有些发慌，深深地吸了一口气。
________ butterflies ________ ________ ________, I breathed deeply.

2 . Even if dinosaurs were ______（被复活）, they probably could not survive in the present day environment.

3 . When life ends, DNA ______ and does not repair itself.

4 . In September 1939, Britain ______ Germany after Germany invaded Poland. The war is known as the Second World War.

5 . Much to their surprise, the results they got from the experiment ______ other medical tests carried out in Australia sharply.（形成对比）

6 . Recently, China has ______ in outer space exploration.（取得一个突破）