7. Research during the past several decades on the nature of language and the processes that produce and make it understandable has revealed great complexity instead of underlying simplicity. (A) that produce and make it understandable has revealed great complexity instead of underlying simplicity (B) of producing and understanding it have revealed not underlying simplicity but great complexity (C) by which it is produced and understood has revealed not underlying simplicity but great complexity (D) by which it is produced and understood have revealed great complexity rather than underlying simplicity (E) by which one produces and understands it have revealed great complexity instead of underlying simplicity 答案：A作者: wikeypig 时间: 2004-1-6 15:47
UP，不明白，请同志们帮我解释一下作者: lizaz 时间: 2004-1-6 21:30
Research [during the past several decades on the nature of language and the processes that produce and make it understandable] has revealed great complexity instead of underlying simplicity.
这里的主语是research，the nature和the processes并列，所以谓语用单数has；A中的produce and make it understandable 用的主动语态，相对与C的被动语态，A更加简洁。