对于下列图示的气候特征，描述正确的是（　　）

    Spring in Nanjing is very short .It is warm and sunny .People (人们) like to go to the parks on sunny days . It is very hot in summer in Nanjing .People do not like to play balls in the afternoon .They like to go swimming in summer . In autumn , it is cool and sunny. Many people like to come to Nanjing in autumn .In winter , it is cold in Nanjing .Boys and girls like to make snowmen and go skating . They have great fun in winter .

机械横波某时刻的波形图如图所示，波沿x轴正方向传播，波长λ=0.8m，质点p的坐标x=0.32m．从此时刻开始计时．