____ volcanoes now for many years, I am still amazed at their beauty as well as their potential to cause great damage.
A．Studied B．To study C．Having studied D．Studying
The trade union in this industry are ____ any reduction in wages.
A．objecting against B．opposed to C．reacted to D．resisting against
Children under six are not __________to school except those of extraordinary intelligence.
A．permitted B．admitted C．accepted D．received
He was so____ a key university that he would work until late into the night.
A．curious about B．anxious about C．desperate for D．concerned about
They also agree that it is the burning of more and more fossil fuels that has resulted ____ this increase in carbon dioxide.
A．from B．of C．in D．to
____ late in the morning, Bob turned off the alarm.
A．To sleep B．Sleeping C．Sleep D．Having slept
