读图，完成以下问题．

如图所示，这是将一些声音输入同一设置的示波器后的波形图，其中音调相同，但响度不同的声音波形是下列图中____和____．（均填“甲”“乙”“丙”或“丁”）

—O-R-A-N-G-E.

下列对达尔文自然选择学说的理解，错误的是（  ）

完形填空

    I like English very much. I think English is very important and 1. Here are my opinions of 2English well.

    I think there are many ways 3learn English. For example, asking the teacher 4 help is very helpful. One of my good 5said he had trouble 6English. His 7 English is very poor. So he reads aloud every morning. Now he can speak English very well. Watching English shows on TV can also be helpful. You can learn many words 8them. Remember "Where there is a 9, there is a way." Believe you can do it 10 .