t think it easy, even if we work hard,______ the South Korea and the North Korea to sit down to talk at present

Our teachers always tell us more English in and out of class.

I was watching the news on TV ________ thepower went off

It was not until the 18th century that manrealized that the whole of the brain was involved in the working of the mind，

sorry, I did not catch you.— ______ repeat the sentence