He _______ a lot of time on research ______ agriculture.A spent into B spent of

问题描述:

He _______ a lot of time on research ______ agriculture.A spent into B spent of

①He spent a lot of time on research into agriculture.他花了许多时间在农业研究上.
②He spent a lot of time on research of agriculture.他花了很多时间研究的农业.
看具体语境选吧.