Although he _______ the danger to his own health, he found it difficult to quit smoking.
A．was very aware of B．well awared of C．was well aware of D．very awared of
We should _______ whatever is true.
A．keep up B．settle down C．stick to D．team up with
He knows so much about Russia that he's universally acknowledged as a(n) _____ on Russian affairs.
A．authority B．routine C．privilege D．boundary
The first few years in the 21st century ______ the rapid rise of China as a world economic power.
A．witness B．has witnessed C．will witness D．have witnessed
Visitors to the National Museum can avoid long lines at the ticket booths by purchasing tickets ____.
A．in advance B．in detail C．out of order D．with caution
She told me that she would not go with us if it ____ the next day.
A．was raining B．rains C．rained D．had rained
