So absorbed     in the experiment that he didn’t even notice it was already over 12 o’clock.

---David has made great progress recently.
--- _____, and _____.

--- Can I help you, sir?
---Yes, please. Do you have any books on cooking?
---There are only a few，______.

In the dark forests _____, some large enough to hold several English towns.

The “Warning” reads: “Under no circumstances _____ be kept near fire!”

________ that he found it difficult to stop at the busy crossing.

Not only _____________ vital for reducing fever, but __________ also other things that it can help with.

— It was cloudy yesterday.
—_________ today.

At the meeting place of the Yangtze River and the Jialing River __________, one of the ten largest cities in the world.

There, ____ Mrs. Tailor, stretching out to gather her precious eggs laid by her hen.