A:倡导节能减排,发展新能源汽车产业
B:提高饮水标准,实现城乡供水一体化
C:提倡健康饮食,推广无公害海水蔬菜种植
D:改良土壤结构,鼓励作物秸秆就地焚烧
如图所示,已知前两个天平两端保持平衡.要使第三个天平两端保持平衡,天平的右边应放几个圆形?请写出你的思路.
—The plane is leaving right now, but Jim hasn't arrived yet.—Well, he said he _____here on time.