一、单项选择：从下列每题所给的选项中，选择一个最佳答案。（15分）
1.I can’t say _______ I miss you. Thr ee years ________ since I saw you last.
A. how long, passed B. how often, past
C. how much, has passed D. how soon, has passed
2.We must stop all kinds of _____________ better environment.
A.pollution to build B.pollution build C.polluting building D.polluting built
3.I t is important ______ us students to make a plan _______ our studies before a new term starts.
A.of, for B. for, for C. to, of D. to, with
