article: Almost all people like flowers. Some people like flowers because of their smells, shapes, colors and so on. Others like flowers because they think different flowers mean different things. Flowers have their own language. For example, red roses mean "love" and sunflowers mean "loyalty ". So people in more than 100 countries have chosen their own _ which say something about their countries' spirit. In 1994, China talked about choosing a national flower. Some people liked the peony  but others liked the plum blossom . They couldn't agree with each other. So it has not been decided yet.
  People like to buy different flowers in different seasons. Where do all the beautiful flowers in shops come from? They may come from far away, so their price is higher.
  a. Farmers grow flowers in their fields.
  b. Planes or trains or buses take the flowers to different places.
  c. Flower shopkeepers buy flowers from the flower markets. They look after the flowers and throw away the broken or bad ones. They cut the flowers to make them more beautiful.
  d. You go to buy the flowers in the shops. When you buy a flower, you're paying lots of people: the farmer, the driver of the plane or train or bus, the seller in the flower market and the flower shopkeeper.
  So you'd better keep your flowers from far away for a long time. But how? Why not dry them? It's easy! Sand drying is a way. Dry, clean sand is one of the oldest things for drying flowers. And it's one of the cheapest.
  *Fill a box half-way with sand.
  *Put the flowers on top of the sand.
  *Put the box in a warm, dry place.
  *Leave the flowers there for one to three weeks.
  *Take them out and they will be dry.
question: Sand drying is everything here in the following but   _  .
options: easy clean old cheap