【单选题】Mr. Brown likes to play_____ volleyball. But Mr. Black likes to play _____chess. [ ]
【单选题】---- Does your wife like tea? ---- Well, she doesn’t really ____ tea; she likes coffee better.
【简答题】A.She doesn't like tea although it's good for her health. B.She likes to drink tea for its good taste. C.She likes beef for its rich nutrition. D.She doesn't like beef at all for its taste.
【单选题】下列四组动物中,不属于软体动物的是( )
【单选题】一平面简谐波,沿 x 轴负方向传播 。 角频率为 w ,波速为 u 。 设 t = T /4 时刻的波形如图所示,则该波的表达式为
B.
y=Acos[ w (t-x/u)+π/2]