We often think of agriculture as planting seeds and harvesting crops. But many crops do not come from seeds. Many kinds of trees and plants are grown from【D1】 1cut from existing trees and plants. This is called grafting (嫁接).
Farmers cut branches or young growths, called【D2】 2, from one plant and place them on a related kind of plant. The branch or bud that is grafted is called a scion (接穗). The plant that【D3】 3the graft is called the rootstock. Over time, the【D4】 4from the two plants grow together. The grafted plant begins to【D5】 5the leaves and fruit of the scion, not the rootstock.
A graft can be cut in several ways. A cleft graft (割接，劈接), for example, requires a scion with several buds on it. The bottom of the scion is cut in the【D6】 6of the letter V. A place is cut in the rootstock to accept the scion. The scion is then【D7】 7placed into the cut on the rootstock. Growth medium is put on the【D8】 8to keep it wet and help the growth.
Grafting can join scions with【D9】 9qualities to the rootstock that is strong and resists disease and insects. Some common fruit trees such as sweet cherries have to be grafted.
In an age of high-technology agriculture, grafting is a low-technology method that remains【D10】 10important.
A) accepts F) desirable K) parts
B) agreeable G) extremely L) pieces
C) blossoms H) gradually M) produce
D) buds I) grow N) securely
E) composes J) joint O) shape 【D1】