中学生网络课堂本课配套习题挑战模式1/5
| A: 海底深度 |
| B: 两山间的距离 |
| C: 打雷处与观察者之间的距离 |
| D: 敌潜艇的位置 |
- 提示1：IOWbnuWjsOaYr+WjsOmfs+WcqOS8oOaSrei/h+eoi+S4remBh+WIsOmanOeijeeJqe+8jOiiq+WPjeWwhOWbnuadpeeahOeOsOixoe+8jOWFtuW6lOeUqO+8muWbnuWjsOWumuS9jeOAgeaOoua1i+mxvOe+pOWSjOaOoua1i+a1t+W6leeahOa3seW6puetiQ==
- 答案：Qw==
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
本课配套习题挑战模式2/5
| A: 只要有障碍物存在就一定能分辨出回声 |
| B: 回声比原声晚0.1秒以上，人耳才能分辨出回声 |
| C: 在较小的房屋内说话就没有回声 |
| D: 以上说法都不正确 |
- 提示1：IOWjsOazouWcqOS8oOaSrei/h+eoi+S4re+8jOmBh+WIsOmanOeijeeJqe+8jOiiq+WPjeWwhOWbnuWOu++8jOW9ouaIkOKAnOWbnuWjsOKAnQ==
- 提示2：IOS6uuiAs+WQrOWIsOWbnuWjsOeahOadoeS7tuaYr++8muWbnuWjsOWSjOWOn+WjsOWIsOi+vuS6uuiAs+eahOaXtumXtOmXtOmalOWcqDAuMXPku6XkuIo=
- 答案：Qg==
5aOw5rOi5Zyo5Lyg5pKt6L+H56iL5Lit77yM6YGH5Yiw6Zqc56KN54mp77yM6KKr5Y+N5bCE5Zue5Y6777yM5b2i5oiQ4oCc5Zue5aOw4oCd77yM5Zyo6L6D5bCP55qE5oi/5bGL5YaF6K+06K+d5Lmf5pyJ5Zue5aOw77yM5YiZQ+ivtOazlemUmeivr+OAgueUseS6juS6uuiAs+WQrOWIsOWbnuWjsOeahOadoeS7tuaYr++8muWbnuWjsOWSjOWOn+WjsOWIsOi+vuS6uuiAs+eahOaXtumXtOmXtOmalOWcqDAuMXPku6XkuIrvvIzliJlC6YCJ6aG55q2j56Gu77yMQemUmeivr++8jOaJgOS7pUTplJnor6/vvJvpgInmi6lC6YCJ6aG544CC
本课配套习题挑战模式3/5
下列现象中利用回声的是（ ）
| A: 渔民利用声呐技术探测鱼群 |
| B: 雷雨天时，先看到闪电后听到雷声 |
| C: 录音棚用软泡沫塑料隔音 |
| D: 医生用听诊器为病人检查病情 |
- 提示1：PHA+5Yip55So5Zue5aOw5rWL6Led56a777yM5Y+v5Lul5o6i5rWL6bG8576k55qE5L2N572uPC9wPg==
- 答案：QQ==
PHA+5Yip55So5Zue5aOw5rWL6Led56a777yM5Y+v5Lul5o6i5rWL6bG8576k55qE5L2N572u77yM5YiZ6YCJ5oupQemAiemhueOAgjwvcD4=
本课配套习题挑战模式4/5
人耳能分清原声和回声的时间间隔应大于0.1秒，所以要能听到回声，人离障碍物的距离应（ ）
| A: 大于34米 |
| B: 大于17米 |
| C: 等于34米 |
| D: 等于17米 |
- 提示1：PHA+5Yip55So5Zue5aOw5rWL6Led56a777yM5rOo5oSP5omA5rWL6Led56a75piv5aOw6Z+z5Lyg5pKt6Lev56iL55qE5LiA5Y2KPGJyPjwvcD4=
- 答案：Qg==
PHA+5aOw6Z+z5ZyoMC4x56eS6IO95aSf5Lyg5pKtMzTnsbPvvIzkurrnprvpmpznoo3niannmoTot53nprvoh7PlsJHkuLozNOexsy8yPTE357Gz44CC5omA5Lul6YCJ5oupQumAiemhueOAgjwvcD4=
本课配套习题挑战模式5/5
一人对着山崖高喊一声，在2s后听到回声，若声速为340m/s，则人与山崖相距（ ）
| A: 680m |
| B: 340m |
| C: 170m |
| D: 34m |
- 提示1：PHA+5Yip55So5Zue5aOw5rWL6Led56a777yM5rOo5oSP5omA5rWL6Led56a75piv5aOw6Z+z5Lyg5pKt6Lev56iL55qE5LiA5Y2KPGJyPjwvcD4=
- 提示2：PHA+5aOw6Z+z5Lyg5pKt55qE5oC76Lev56iL5Li6MzQwbS9zw5cycz02ODBtPC9wPg==
- 提示3：PHA+5YiZ5Lq65LiO5bGx5bSW6Led56a75Li6PGltZyBzcmM9Imh0dHBzOi8vcDIucWluZ2d1by5jb20vRzEvTTAwLzFFL0I5L3JCQUNGRk44RjlPaFItY01BQUFDV1JibG9KNDIwMS5wbmciIGRhdGEtY2tlLXNhdmVkLXNyYz0iaHR0cHM6Ly9wMi5xaW5nZ3VvLmNvbS9HMS9NMDAvMUUvQjkvckJBQ0ZGTjhGOU9oUi1jTUFBQUNXUmJsb0o0MjAxLnBuZyIgaGVpZ2h0PSI1MiIgd2lkdGg9IjcxIj49MzQwbTwvcD4=
- 答案：Qg==
PHA+5aOw6Z+z5Lyg5pKt55qE5oC76Lev56iL5Li6MzQwbS9zw5cycz02ODBt77yb5YiZ5Lq65LiO5bGx5bSW6Led56a75Li6PGltZyBzcmM9Imh0dHBzOi8vcDIucWluZ2d1by5jb20vRzEvTTAwLzFFL0I5L3JCQUNGRk44RjlPaFItY01BQUFDV1JibG9KNDIwMS5wbmciIGRhdGEtY2tlLXNhdmVkLXNyYz0iaHR0cHM6Ly9wMi5xaW5nZ3VvLmNvbS9HMS9NMDAvMUUvQjkvckJBQ0ZGTjhGOU9oUi1jTUFBQUNXUmJsb0o0MjAxLnBuZyIgaGVpZ2h0PSI1MiIgd2lkdGg9IjcxIj49MzQwbe+8m+aJgOS7pemAieaLqULpgInpobnjgII8L3A+
