一物体的运动方程为s=3+t2,则在时间段[2,2.1]内相应的平均速度为( ).
A.4.11
B.4.01
C.4.0
D.4.1
答案:D
根据题意可得:=4.1
既走表发汗,又走里温经的药是()
A.炮姜
B.香薷
C.艾叶
D.麻黄
E.桂枝
Water is (41) important of all the things we (42) and drink. Not many people understand this, (43) it’s quite true. The human body (人体) can go (44) food for a long time, but two (45) three days without water can usually (46) people die. Many people don’ t understand how much water the human body needs to work well and many people do not drink (47) , even (48) hot weather. Our body is (49) water, about 65% to 75%, ff we do not have enough water, we’ll (50) tired and many will get ill. So you see, how important water is to us all.
[A] make [B] get[C] let