A good deal of money has been spent on books.为什么这里是has been,

因为这里是现在完成时的被动语态,
到目前为止,大量的钱已经被用在这些书上了.----- “已经”,用现在完成时.“被用在”,被动语态
被动语态的格式是 be done,钱被花了,是the money is spent,
再加上现在完成时的格式 has done sth.被动的就是 has been done,那么就是has been spent
所以就成这个样子了,因为钱是被动
如果主语是人,才是 sb has spent some money.