The city is built _____ two rivers come together.
Some animals carry seeds from one place to another, ______ plants can spread to new places.
The crazy fans___________ patiently for two hours, and they will wait till the movie star arrives.
When ____ to danger and conflict, men tend to increase blood pressure, ____ nervous or anxious.
It is believed that _____ European scientist invented _______.
I don’t think David could have done such a stupid thing last night, ____?