【单选题】The figure shows a graph of the market for pizzas in a large town. If the price falls from $10 to $7 per pizza, the quantity of pizzas demanded will
【单选题】The figure shows a position-versus-time graph of the motion of a car. Describe the velocity and acceleration during segments OA, AB, and BC. Which item is Not correct?【图片】
A.
In segment OA, the velocity is positive and constant.
B.
In segment OA, there is no acceleration.
C.
In segment AB, the velocity is increasing.
D.
In segment AB, there must be acceleration.
E.
In segment BC, the velocity is not constant.
F.
In segment BC, this velocity is greater in magnitude than the velocity in segment OA.
【简答题】Mr. Smith 36 from London. Now he is in China. He is 37 .He teaches 38 a middle school. He works very hard. His students like 39 very much. He can 40 a little Chinese. His students often teaches h...