作业帮the invention___took her two years will do good to the world.a.which b./ c.on which d.it
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the invention___took her two years will do good to the world.a.which b./ c.on which d.it
A
提前，与which组合，做invention的定语也可以是这样the invention which she spent two years on will do good to the world. C，定语从句，she