如图所示为t1和t2两个时刻的波形图象.若t2-t1=0.5s,则: (1)如果

题型:问答题

问题:

如图所示为t1和t2两个时刻的波形图象.若t2-t1=0.5s,则:

(1)如果波向右传播,且3T<t2-t1<4T,则波速多大?

(2)如果波向左传播,且2T<t2-t1<3T,则波速多大?

(3)如果波速v=68m/s,则波向哪个方向传播?

考点:横波与纵波波长、频率和波速
题型:问答题

用方框中所给词的适当形式填空,完成短文。

Hello!  I’m Jenny. There  小题1:     many festivals at our school. Let me 小题2:you!  This month is October. All the 小题3:   love October. In October, there is a Sports  Festival. We have a basketball game 小题4:  a volleyball game during (在…期间) the festival. In the middle (中旬) of this month, we小题5:   an English speech contest during the English Festival. October 19th is the day for a school trip. We go to Beijing  小题6:   the teachers. On the last day of this month, there is a Music Festival. On that day, we can enjoy beautiful songs, piano music and so on. It is wonderful. Next month, there is  小题7:    Art Festival. Students often display  (展示) 小题8:   pictures on that day. I study and play games小题9: my school. It gives 小题10:   happiness (快乐). I love my school very much.

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加油机基本工作原理图中的箭头线段表示()。

A、机械传送方向

B、燃油流向

C、电子信号传送方向

D、电源方向

题型:问答题

UnicomG网900MHz的频率号是96,它的下行频率可能是()

A.827.2MHz

B.909.2MHz

C.452.2MHz

D.872.2MHz

E.954.2MHz

题型:问答题

涨价预备费之计算基数为( )之和。

A.建筑工程费

B.设备及工具购置费

C.安装工程费

D.基本预备费

E.涨价预备费

题型:问答题

What’ s the doctor’ s advice
[A] Eating more. [B] Sleeping more. [C] Doing more exercises.

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