能从食物中获得更多的能量。

　　4．选F　本空承上启下，指出了细菌对维持生态平衡的作用。

　　5．选C　本空为本段的主旨。根据该空后面的内容可知，一些食物的制作过程也需要某些菌群的参与。

第二节 完型填空 (共20小题；每小题1.5分，满分30分)

　　阅读下面短文，从短文后各题所给的A、B、C和D四个选项中，选出可以填入空白处的最佳选项。

　　Cindy glanced nervously at the clock on the wall. "They should be home now，" she 1 as she put the finishing touches on the chocolate cake she was 2 . It was the first time that she had 3 to make a cake, and to be honest, it wasn't exactly a great 4 . The cake was lumpy (多块状物的) and the 5 was in a mess.

　　But Cindy wasn't 6 about the mess. She was just anxious for her parents to return home so she could 7 her gift to them. She turned off the lights and waited 8 in the darkness.

　　Soon she heard her parents' 9 . When they opened the door, she 10 the lights and screamed, "Ta­daaa！" Then she gestured towards the table in the kitchen, where a chocolate cake was waiting for their 11 .

　　But her mother's eyes 12 made it all the way to the table.

　　"Just look at this mess！" she complained. "How many times have I talked to you about 13 up when you have finished your play? You'd better tidy the room right now！"

　　"Honey，" Cindy's father cut in gently, "take a look at the 14 ."

　　"I know it's a mess，" Cindy's mother said 15 . "The whole kitchen is a disaster. I can't 16 looking at it." She went into her bedroom angrily. She never saw the cake!

　　 17 ， Cindy's mother isn't the only parent who can't see the forest for the trees. Our children do need to learn to have 18 ， but it needs to be taught carefully. As a parent, we must never 19 that we're not teaching lessons but teaching children. That 20 there are times when we need to see the mess in the kitchen, and also times when we need to see the cake.

　　语篇解读：一个小女孩为自己的父母做了一个蛋糕，但也将厨房弄得乱七八糟。当父母回来的时候，她妈妈却只看到厨房的混乱，而对蛋糕视而不见。

　　1．A.wondered　　　　　　 B．laughed

　　C．hoped D．said

解析：选D　小女孩独自一人在家做蛋糕，她看了一下表，自言自语地说："他们该到家了。"