Im dumb so help

What does water came out from a rock mean in this poem and why is it compared to the radio waltz? time was away and somewhere else. the waiter did not come, the clock forgot them and the radio waltz came out like water from a rock: time was away and somewhere else.

Dogs make wonderful pets because they us stay happy and healthy. the topic sentence is "dogs make wonderful pets." , is this correct? i keep doubting myself.

In the song mallam sile sings in lines 113 through 130 the knife probably represents