—Is using a mobile phone harmful to people’s health? —Scientists ________ this problem, and no exact conclusion has been drawn yet. A. have studied B. were studyingC. have been studying D. had been studying 答案:【解析】选D。考查as. . . as. . . 结构。句意为:到目前为止他们拥有的设备与我们拥有的一样多。equipment是不可数名词,不能用many修饰,所以可排除A、C两项。根据句意可知正确选项为D。10. 下列关于亚洲自然地理特征的叙述,正确的是() A. 以山地、局原为主,平均海拔居各洲之首 B. 季风气候显著,包括热带、三种季风气候类型 C. 大河都发源于中部高山地带,流入太平洋和印度洋 D. 湖泊分布广泛,淡水湖面积居世界之首