Solid, because the atoms maintain their form and do not take the shape of their container. The particles share tight, close bonds due to this set shape
(c) is the correct choice.
El Nino (a), Earth's orbit (b), and solar energy output (d) are all "natural" occurrences. You can't do a thing aboutum.
Fossil fuels ... or, more precisely, humanity's use of vast quantities of fossil fuels as a convenient source of huge quantities of energy ... and the subsequent increase of Carbon Dioxide in the planet's atmosphere, is not the result of "natural" processes. It's the result of human efforts to <em>alter and control</em> Nature, through <em>artificial</em> processes.
After years of observation, Hubble made an extraordinary discovery. In 1923 he spotted a Cepheid variable star in what was known as the Andromeda Nebula. Using Leavitt's techniques, he was able to show that Andromeda was nearly 1 million light years away and clearly a galaxy in its own right, not a gas cloud.
The weight of the cooler is (mg). That's (26)(9.8) = 254.8 Newtons.
Its gravitational potential energy while it's up in the top row is (mgh). That's (254.8)(17.5) = 4,459 Joules.
That's how much work it took to get the cooler up to the top row, and that's the energy it gives up when it moves back down to the bench.
In order to bring it down . . .
-- Gravity does 4,459 joules of work on the cooler.
-- The team assistant does NEGATIVE 4,459 joules of work on it.
