You look exhausted. You __________ in the garden all day.
A. must have been working B. must have worked
C. must be working D. can’t have worked

Ann: “Does the global warming worry you?” Mathew: “ __________”.
A. What a shame! B. Oh, it’s hotter and hotter
C. I can’t bear to think about it. D. I don’t like hot weather.

Peter: “Is it important?”. Thomas: “_________________”.
A. Not on your life ! B. It’s a matter of life and death!
C. No worry, that’s nothing . D. It’s ridiculous.

Determining the mineral content of soil samples is an exacting process; _________ experts must
perform detail tests to analyze soil specimens.
A. so that B. however C. afterwards D. therefore

For the first time _________, large portions of the universe can be observed simultaneously.
A. since history B. in history
C. history began D. of the beginning of history

The issue _________ question is more complex than you think.
A. from B. at C. on D. in

It is _________ opportunity to see African wildlife in its natural environment.
A. an unique B. a unique C. the unique D. unique

He has been waiting for this letter for days, and at _________ it has come.
A. last B. the end C. present D. the moment

Some drivers seem to expect everyone else to get _________ their way.
A. away from B. out of C. off D. after

The smell was so bad that it completely _________ us off our food.
A. set B. took C. got D. put