investment in 还是 investment on

investment in 还是 investment on, 对于介词的用法不是很熟悉

对了，再求教一个，inhibition for/of disease

应该选用哪个介词

investment
KK: []
DJ: []
n.
1. 投资;投资额;投资物[U][C][(+in)]
参见：http://www.baidu.com/s?lm=0&si=&rn=10&ie=gb2312&ct=1048576&wd=investment&tn=baidu

inhibition of sth.
参见：http://love.iciba.com/inhibition+of+fluorescent+foci/