估算． 58×9≈397×5≈403×6≈92×5≈92÷3≈78÷4≈52÷5_爱下问搜题

搜题请搜索小程序“爱下问搜题”

问题解答题

估算．

58×9≈	397×5≈	403×6≈	92×5≈
92÷3≈	78÷4≈	52÷5≈	59÷6≈

答案

58×9≈540

397×5≈2000

403×6≈2400

92×5≈450

92÷3≈30

78÷4≈20

52÷5≈10

59÷6≈10

补全对话，情景问答

根据句意，完成下列句子。

1. How old is the tree?

It's about (10) years old.

2. How old is the man?

He is (31) years old.

3. is the girl?

She is eleven years old.

4. is the boy?

He is l.4 metres tall.

5. How old is the Palace Museum?

It's about (500) years old.

判断题

直流熔断器的配置的基本要求是消除寄生回路和增强保护功能的冗余度