If _________, the bird flu would produce a powerful poison that would kill the patients.A. not treat B not treated C untreated D. Both B and C
Once telling him the truth, _____.
Willpower is a kind of quality, _____ is _____ it takes to do anything well.
I was so familiar with him that I recognized his voice _____ I picked up the phone.
It’s reported that the police will soon ____ the case of two missing children.
Tom is keen _____ surfing the Internet in his spare time.