Answer:
A man calls his dog from the opposite side of the river. The dog crosses the river without getting wet, and without using a bridge or boat. How?
What has a big mouth, yet never speaks?
In we go, out we go. All around and in a row. Always, always steady flow. When we'll stop, you'll never known. In we go, out we go.
What loses its head in the morning and gets it back at night?
What can be measured but not seen?
A word of five letters, Upside down is the same, A shark does this, But itβs not to blame. What is the word?