兄弟两人共同投资500万元合办企业，后来弟弟又追加20万元投资额．这时，哥哥的投资额恰好是弟弟投资额的3倍．则哥哥投资了______万元．

The wholesaler obtains higher selling prices for ______.

A．small parcels he sells

B．goods he buys in bulk

C．the service he provides

D．the information he offers