The United States grows nearly _____ of the world's grain and supplies a half of all the exports of grain in the world.
A.one third B.one fourth C.one sixth D.one seventh正确答案B
The United States grows nearly _____ of the world's grain and supplies a half of all the exports of grain in the world.
A.one third B.one fourth C.one sixth D.one seventh正确答案B
