--- Never before in China ______ for the farmers.

--- You’re telling me. They extremely content with the new farming policies.

A.    had so much been done                       C.    so much has been done

C.    has so much been done                        D.    has done so much

小玉外出游玩，遇到被救上岸时呼吸停止，有微弱心跳的溺水儿童。李明回忆学过的急救知识，想尽快对其实施求治。在他回忆的以下做法中，不恰当的是（ ）

A．使溺水儿童仰卧，头后仰，衣领解开

B．清楚口鼻内的污物体、异物

C．一手托住后脑，一手托起下颌，口对口吹起

D．每分钟吹气15—20次