Answer:
Without this, eating food and Steven Spielberg's career would be very different.
My first is a creature whose breeding is unclear. My second, a price you must pay. My whole can be found in the river of Time and refers to events of today.
If a man carried my burden, he would break his back. I am not rich, but leave silver in my track.
What has 4 legs in the morning, 2 legs in the evening and 3 legs in the night?
I run around the city, but I never move.
If itβs information you seek, come and see me. If itβs pairs of letters you need, I have consecutively three. What am I?