The Nuclear Security Summit is an initiative of Mr. Obama, considers nuclear terrorism to be one of the greatest threats to international security.
The novel was so interesting that he read it _____ in a single day.
After the flood, no house in the village ______,
-----Hi, Nancy, I didn’t know you had come back. So have you graduated from college? ---- Yes. I _____ French for 5 years in Nanjing.
---- Could I have a word with you? ---- Sorry, I am busy ______. Shall we do it later?
---Why didn’t you go to yesterday’s meeting? ---I would have but I ______ too busy working on the important experiment.