Answer:
I carry you down a gentle stream.
I drift forever with the current and flows to your everyday life. I make living easy but I am good at killing people too.
I'm blue at day and black at night. I do contain some creatures born and died. What am I?
I am black and white. I have strings I have keys. I make sound without my lips. I make dough with no flour
What is harder to catch the faster you run?
Though not a plant, has leaves. Though not a beast, has spine. Though many wouldn't need this thing, It's more valuable than wine.