非谓语英语问题
C19 ._____ for a long time,most of the crops in this area died from lacking water.
A.Being no rain B.There was no rain
C.To be no rain D.There being no rain
为什么选C,A和C如何辨析
C23 .Charles Babbage is generally considered ____ the first computer .
A .to invent B .inventing C .to have invented D .having invented
为什么选C,不选D