A:马和驴的染色体不能共存
B:染色体结构发生变化
C:减数分裂中同源染色体联会紊乱
D:马和驴的遗传物质有本质区别
—I think it's really necessary. It is reported that the food that Chinese people _____ every year is enough to feed 200 million people for a year.