问题
选择题
节约是一种美德，节约是一种智慧．据不完全统计，全国每年浪费食物总量折合粮食可养活约3亿5千万人．350 000 000用科学记数法表示为（ ）
A．3.5×107
B．3.5×108
C．3.5×109
D．3.5×1010
答案
350 000 000=3.5×108．
故选B．
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节约是一种美德，节约是一种智慧．据不完全统计，全国每年浪费食物总量折合粮食可养活约3亿5千万人．350 000 000用科学记数法表示为（ ）
A．3.5×107
B．3.5×108
C．3.5×109
D．3.5×1010
350 000 000=3.5×108．
故选B．
| 完形填空。 | ||||
| Do you live in a city? Do you know 1 cities began? Long long ago, there were only 2 people in the world. These people 3 from place to place. They moved over the land, hunting animals for 4 . No one knows how or when these people learned about growing food. But when they 5 that, their lives clanged. They didn't have to look 6 food any more. They 7 stay in one place and grow it. People began to live near one another.And so the first villages grew. Many people came to work in the villages. These 8 became very big. 9 machines came along, life in the villages changed again. Factories 10 . More and more people lived near the factories. And then the cities began and grew very big. | ||||
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