《辩论——美国制宪会议记录》一书评论道：《联邦宪法》是一套“地域和体制的双向平衡机制”。这体现了该宪法的主要特点是(     ) 

    Mary is a student. She enjoys ____(run). Every morning, she starts to run near her home____ (介词) six o'clock. She also ____ (like) ball games. After school, she ____ (join) her classmates to play basketball. She ____ (eat) well too. She has three ____ (meal) at school. Her favourite food is ____(dumpling). But the dining hall is small with only ten ____ (table). The students are always ____(wait) there. Now it's time for dinner. Mary is ____ (walk) to the dining hall.

悬浊液、乳浊液和溶液的共同点是    (    )

雾霾是目前我国常见的一种灾害性天气，下列表示霾的天气符号是（ ）

人体内氢随化合物在生物体内代谢转移的过程如图所示，下列分析合理的是（　　）