121.As a result of medical advances, many people that might at one time have died as children of such infections as diphtheria, pneumonia, or rheumatic fever now live well into old age. (B) who might once have died in childhood (D) who in childhood might have at one time died 答案是B,没有问题
我想问D如果改为who in childhood might once have died 有问题吗??