. Thousands of foreigners were______ to the Shanghai World Expo the day it opened.
—Why do you look worried?—Fred left the company half an hour ago. His work ________ unfinished since.
She ought to stop working; she has a headache because she ________ too long.
When I called you this morning, nobody answered the phone. Where ________?
—Did Alan enjoy seeing his old friends yesterday? —Yes, he did. He ________ his old friends for a long time.
—Will you go to the park now? —Not until I ________ my physics exercises.