The two Chinese scientists have made a wonderful discovery, which marks a major _______ in the basic research in the field.

A．reform

B．approach

C．boundary

D．breakthrough

经产妇，经 * * 顺产一男婴，目前诉说 * * 胀痛，下腹总阵痛，查 * * 胀，无红肿，子宫硬，脐下2指， * * 流血不多。

针对下腹痛的症状，对产妇的是( )

A．正常产后宫缩痛

B．属于异常疼痛

C．用止痛药物

D．一周后消失

E．用宫缩剂