1 . We can’t put prefix “un-” to ________ to give it the opposite meaning.

A．correct

B．comfortable

C．certain

D．interesting

2 . “For a moment, he was speechless. Happiness seemed to fill his body and stick in his throat.”
Which word is formed in the same way as “speechless”?

A．disappear

B．dangerous

C．footprint

D．impossible

3 . Which of the following suffixes(后缀)means "without"?

A．–able

B．–ful

C．–ous

D．–less