单选题
Babbage was a
prolific
inventor, whose inventions include the ophthalmoscope for examining the retina of the eye, the skeleton key, the locomotive "cow catcher", and the speedometer.
【正确答案】
A
【答案解析】解析：四个选项的意思分别是：productive多产的，富有成效的；obstinate顽固的；eminent杰出的；shrewd精明的。句意是，Babbage是一名多产的发明家，发明的东西包括用于检查视网膜的检眼镜、万能钥匙、可移动排障器和速度计。所以正确答案是A选项，如：We had a productive meeting that solved some problems．(我们开了一次富有成效的会议，解决了一些问题。)