Complete the following sentence with a (compound) word derived from the one(s) given in bracket.
People who leave home in the morning slamming doors behind them are likely to be less （ ） than those who leave home with a smile. (product)
【正确答案】：PRODUCTIVE
【题目解析】：
根据前文be less说明空格处应该填形容词，product的形容词形式为productive多产的，高效的，且符合句意。句意：早上离开家的人，在他们身后砰地关上门，可能比那些带着微笑离开家的人工作效率更低。