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问题 问答题 简答题

简述鱼类血液循环的特点？

答案

参考答案：

①鱼类属低等脊椎动物，心脏较原始，只有一心耳、一心室。

②由于鱼类用鳃呼吸，血液或淋巴液在管道内循单一方向环流不息。

③经过心脏的血为含氧量低的静脉血。

选择题

要从Al2（SO4）3溶液中制得Al(OH)3，最好的方法是

A．加人NaOH溶液

B．加人氨水

C．加人Ba(OH)2溶液

D．加人Ca(OH)2溶液
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填空题

Questions


·You will hear five conversations taking place in restaurants and the customers are complaining about something.
·Before you listen, read the list of statements, five of which are summaries of how these problems are solved.
·Then listen carefully and match the statements (A-F) with the conversations that are about them respectively.
·There is one extra statement that you don’t need to use. You will hear the passage twice.
A. it is suggested that she change her order to some sirloin because it is tender.
B. She is asked to send in the bill if she likes to have it cleaned.
C. The head waiter goes to fetch some clean ones immediately.
D. He offers to sponge it with a little warm water.
E. He is advised to choose another wine instead.
F. The head waiter will deal with it himself.

Questions


·You will hear five conversations taking place in restaurants and the customers are complaining about something.
·Before you listen, read the list of statements, five of which are summaries of how these problems are solved.
·Then listen carefully and match the statements (A-F) with the conversations that are about them respectively.
·There is one extra statement that you don’t need to use. You will hear the passage twice.
A. it is suggested that she change her order to some sirloin because it is tender.
B. She is asked to send in the bill if she likes to have it cleaned.
C. The head waiter goes to fetch some clean ones immediately.
D. He offers to sponge it with a little warm water.
E. He is advised to choose another wine instead.
F. The head waiter will deal with it himself.
查看答案