四、閱讀測驗 What do you do with your orange peels and corn cobs after you are done eating? Most people throw them into a
trash can. However, most food leftovers do not have to go into the trash. They are biodegradable, which means that
they can be broken down by bacteria into natural materials.
For people who like to garden, they often put their fruit and vegetable scraps in a special place known as a
compost pile. A compost pile is an outdoor spot where food waste can break down into compost for gardeners to use.
This process usually takes several months. Once the compost is created, people spread this mixture in their gardens
to add nutrients to the soil. The compost in the soil helps new plants grow in gardens.
How can people take care of a compost pile? It needs air, water, and heat. Bacteria and other microorganisms
break the food waste down into more basic elements, like water and carbon dioxide. This process requires oxygen, so
people use a shovel to turn compost regularly and help air reach all parts of the pile. The pile cannot dry out, so it has
to be covered to keep moisture in. Finally, heat speeds up the process. This means a compost pile should be in the sun
for at least part of the day.
Food leftovers are not the only things that can turn into compost. People can also add yard waste, like grass
clippings, dried leaves, and straw. In fact, people should add these things to create a healthy balance in their compost.
One reminder is not to add any weeds to a compost pile! Sometimes, seeds are left behind in the compost. This can
be a welcome surprise if people later find a tomato plant sprouting where they had not planted one. The tomato seed
was hiding in the compost, waiting to begin a new life in the garden.
【題組】17. According to the passage, why do gardeners use a compost pile?
(A) To save money
(B) To reduce food waste
(C) To make use of bacteria
(D) To provide nutrients to the soil