Question

Only by ______ your attention ______ what you are learning can you learn it well.

A．focus；on

B．pay；on

C．focusing；on

D．paying；on

Answer 1

C

by是介詞，后面用動(dòng)名詞形式。句意：只有把精力集中在你所學(xué)的東西上，你才能學(xué)好它。focus...on...“把……集中在……上”，固定短語(yǔ)。