根据首字母或所给中文提示，写出正确的单词完成句子。

1. The headmaster excitedly a____________ the school sports meeting began.

2. Obama is a good speech maker and his first speech as president made a strong i_________ on his

    audience.

3. The farmers in this area had a good harvest last year thanks to the s________ farming.

4. His friends were ___________________(热情)and encouraged him to publish his ideas.

5. Berlin sounds fascinating from your ____________________(描述).

椭圆齿轮流量计属于：（）。

A.差压式流量计

B.容积式流量计

C.速度式流量计