It was not until he arrived at the office_____ realized he had forgotten the key.
---What’s the matter with you?---After the long walk, my legs ______ and I couldn’t go any further.
He hasn’t slept at all for three days. _____ he is tired out.
---Will Li Ming attend the concert by Jay Chou? ---No. He _____ for the coming speech contest lately.
The film is said to have cost _________ money because of lots of famous stars performing in it.
_____ maths is concerned, Tom is the best student in our class.