—You look a bit worried.What has happened? —So I do.You see,the computer I got ________ yesterday doesn’t work again.
Several weeks had gone by _______ I knew the painting was missing.
Mr. Alexander doesn’t just write for fun; _______, writing is his bread and butter.
He sent me an e-mail, ________ to get further information.
---Mr. Smith must know a lot about Chinese history. ---________. He has studied it for years.
While watching television, ________.