作主语表示人时,that和who一般可以互换;作宾语表示人时,that和 whom一般可以互换;作主语、宾语表示物时,that 和which一般可以互换,而且都可以省略。 【例2】The scientist and his achievements___you told me about are admired by us all .(2008年广东梅州市) A. th...