A streamlined body is a shape that decreases the friction drag between a fluid, such as air and water, and an object that passes through that fluid. Drag is the force which reduces the speed of the motion.
Copper is less reactive than zinc. Zinc will replace the copper from its salt solution. When the copper sulphate solution is stored in a zinc pot, copper is replaced by zinc, in the copper sulphate solution.
Zn + CuSO4 → ZnSO4 + Cu
So copper sulphate solution cannot be stored in a zinc pot.