—I think you owe me some money? —______? My money has never been tight.
Thousands of foreigners were ________ to the Shanghai World Expo the day it opened.(2010·江苏)
It is uncertain ________ side effect the medicine will bring about, although about two thousand patients have taken it.(2010·浙江)
Part of the reason Charles Dickens loved his own novel, David Copperfield, was ________ it was rather closely modeled on his own life.(2010·北京)
He didn't go by bike with me.That's ________ there was something wrong with his bike.
They________have arrived at lunchtime but their flight was delayed.(2011·全国 )