1．Mr Cook is a man with a strong will. After repeated_____he finally succeeded in his
experiment.
A．announcements B．decisions C．remarks D．attempts
2．—How about your travel?
—You can hardly imagine what difficulty we have had_______the vast desert.
A．exploring B．explored C．to explore D．explore
3．________frightened us________a tiger turned up suddenly in front of us.
A．It was； that B．What；was C．It；that was D．What；was that
