About 71% of the earth’s surface ______ covered with water, but 20% of the world population ______ have access to safe drinking water.

A．is; doesn’t

B．are; don’t

C．are; doesn’t

D．is; don’t

下列哪项不是ADHD多动冲动型的诊断标准（）

A.坐着手脚不停地扭动常显得烦躁不安

B.很难安静地参加游戏或课余活动

C.日常生活中很健忘

D.常在问题尚未问完时就抢着回答

E.常常打断或干扰别人的讲话或游戏