A-A+
The estimate is based on the______.A．direction
问题详情
The estimate is based on the______.
A．direction of the hill
B．accepted speed of sound
C．interval between sound and echo
D．both B and C
参考答案
正确答案：C
解析：从第一段最后一句我们可以找到答案：通过测定声音与它反射之间的间隙就可以测算与某一物体之间的距离，所以正确答案为C。
