第34题: [单项选择]Since the energy crisis, these big cars have become a real liability. They cost too much to run. A. lack of reliability B. substitute C. costly means of transport D. disadvantage 参考答案:D 答案解析:lack of reliability缺乏可靠性;substitute代替品;costly means of transport昂贵的交通方式;disadvantage缺点,不利条件。