A professor, as well as several students, ________ in the lab.

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A．are doing experiments

B．is doing experiments

C．have been doing experiments

D．has been done experiments

What they need most ________ and they feel very happy.

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We found the lake completely ________.

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Do you know ________ its food?

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A．how does the sperm whale find

B．how the sperm whale find

C．how the sperm whale finds

D．how do the sperm whale find

Do come and join us. We'll be sorry if you ________.

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There're nearly one hundred and twenty teachers in our school and ________ of them are women.

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When you leave the room, don't forget to keep the door ________.

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________ from the top of the hill, the hospital looks like a beautiful park.

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How I wish it ________ spring all the year round.

[　　]

Have you ever heard the song ________ in English?

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