Miss Li，a humorous teacher，taught maths last term.（ ）
A．usB．ourC．oursD．ourselves
Rules are helpful to us，______ we have to follow them．（ ）
A．soB．butC．orD．because
Tim is going to give his father a surprise ______ Father's Day．（ ）
A．inB．atC．onD．by
Ladies and gentlemen，attention please!I have ______ important to tell you．（ ）
A．nothingB．somethingC．everythingD．anything
I like hiking in the forest because the air is pretty ______．（ ）
A．freeB．dirtyC．pollutedD．fresh
﹣______ do you usually share happiness with？
﹣My parents and my best friend．（ ）
A．WhoB．WhoseC．WhatD．How