Question

It is our duty ______much attention to ________ our best to keep our city clean.

A．to pay, trying	B．paying, trying
C．pay, try	D．to pay, try

Answer 1

A

解析試題分析：句意: 注重盡我們最大努力保持我們的城市清潔是我們的責任。pay attention to是固定詞組，注意……。try one’s best to do 盡力做，是固定詞組。不定式to pay much attention to try our best to keep our city clean是句子的真正主語，代詞it是形式主語。據句意，故選A。
考點：考查動詞短語和非謂語動詞。