Are there any parallels that happened during the oxygen catastrophe and modern-day climate change?

Density of salty water as compared to the density of pure water is(a) is less(b) is always equal(c) is always more(d) may be less or more

Two carts, one of mass 2m and one of mass m, approach each other with the same speed, v. when the carts collide, they hook together. assume that positive momentum is to the right. which graph best represents the momentum of both carts over time, before and after the collision?

Ascientist wants to test ways to reduce pollution in lake . what is the bestway of doing this