The government has taken ______measures to stop pollution, hoping to call the attention of all people

to face the problem. [      ]

A. a great many

B. a great deal of

C. a plenty of

D. a large amount of

甲、乙两质点同时由同一地点沿同一方向做直线运动，它们的v-t图线如图所示，则（）

A.甲做匀速运动，乙做加速运动

B.2s前甲比乙速度快，2s后乙比甲速度快

C.在第2s时乙追上甲

D.在第2s内，甲的平均速度小于乙的平均速度