填空题

Directions: This part consists of two short passages, In each, there are ten mistakes, One in each underlined sentence or part of a sentence. You may have to change a word, add a word or just delete a word. If you change a word, cross it out with a slash ( — ) and write the correct word near it. If you add a word, write the missing word between the words (in brackets) immediately before and after it. If you delete a word, cross it out with a slash ( — ) . Put your answers on the ANSWER SHEET.
Passage One
How to Get Preserved as a Fossil
(71) Unfortunately the chances of any animal become a fossil are not very great, and (72) the chances of a fossil then being discovered many thousand of years later are even less. (73) It is not surprising that all the millions of animals that have lived in the past (74) we actually have fossils of only very few.
(75) There are several ways into which, animals and plants may become fossilized. (76) First, it is essential that the remains are buried, as though dead animals and plants are quickly destroyed (77) if they remain exposed the air. Plants rot, while insects and hyenas eat the flesh and bones of animals. (78) Finally, the few remaining bones soon disintegrate the hot sun and pouring rain. If buried in suitable conditions, however, animal and plant remains will be preserved. (79) The same chemicals change sand and silt into hard rock will aim enter the animal and plant remains and make them hard too. (80) When this happens, we say that they become fossilized.