1．On account of the development of the economy, the environment is seriously polluted and we must ________ the emission of the carbon dioxide.
A．cut in B．cut off
C．cut up D．cut down
答案与解析：D 句意：由于经济的发展，环境受到了严重的污染，因此我们必须减少二氧化碳的排放量。cut down“减少；削减”；相当于reduce。cut in“插嘴；突然插入”；cut off“切断”；cut up“切碎”。
2．—Hi, David! How was your trip to Beijing?
—Wonderful! I had never had ________ holiday in my life.
A．a most exciting B．a more exciting
C．the most excited D．the more excited
答案与解析：B 形容词或副词的比较级与否定词连用可表示最高级概念，排除A、C两项；excited“激动的”，常用于修饰人，exciting“令人激动的”，常用于修饰物，故B项正确。
