填:is...it
A set of keys is on the table.Let me get it .
类似A set of keys这样的量词短语作主语时,谓动根据量词的单复数来决定.
此题A set 为单数,故用is,相应地后面就用it 了.
又如:A pair of chopsticks is on the table.
桌子上有一双筷子.
10 pairs of chopsticks are on the table.
桌子上有十双筷子.