英语问题--阅读理解58

英语问题--阅读理解58
Students in a science class are using wormsto compost the soil.First ,food wastes from the cafeteria are taken to thegreenhouse .Then the worms break down the leftovers to create fresh soil.Lastmonth,students began to harvest their first crop of vegetables.HannahJull,11,says the crops are doing well.”We have so much fun and everyone isgoing to like the food we’re growing .”Niamone believes the school garden hasinspired kids to plant gardens at home .”The project taught us that with alittle hard work,you can make a healthier choice ,”she says.”You just have totake that one first step.”
58.Food wastes are taken to thegarden to _______.
A.make the soil fresh B.feed the worms
Worm分解食物残渣,分解后的产物（无机盐）使土壤肥沃,B直接,A间接.有时答题要选最直接那个,有时选间接的,为什么?