跟回声现象有关的是（） A．一切发声体都在振动 B．船只_爱下问搜题

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问题多选题

跟回声现象有关的是（　　）

A．一切发声体都在振动

B．船只利用声音测定距冰山的距离

C．雷雨时，人们总是先看到闪电后听到雷声

D．医学上利用超声波检测病情

答案

BD

补全对话，情景问答

给问句选出恰当的答语。

( ) 1. What's her name?
( ) 2. What can you see?
( ) 3. Are they new?
( ) 4. What do you like?
( ) 5. What's for lunch?
( ) 6. Would you like some fish?
( ) 7. How much for one pencil?
( ) 8. What is your favourite food?
( ) 9. Is it long or short?
( ) 10. Where is Danny?

A. Dumplings.
B. It's long.
C. No, thanks.
D. I can see my teacher.
E. He is in the gym.
F. Her name is lucy.
G. I like meat.
H. My favourite food is rice.
I. Yes, they are.
J. One yuan.

判断题

我国心理学家为促进学生德、智、体的全面发展，主张将学生的学习分为信号学习、刺激—反应学习、连锁学习等八类。