Answer:
A and C
Explanation:
The rock layers must have formed at different times because they contain two different biozones. The rock layer containing the trilobites must have formed before the one containing the ammonites. The key thing to note here is that the Trilobites only lived from 540 to 248 million years ago. And that the Ammonites were from 245 to 65 million years ago. So there's a 3 million year gap between these 2 different creatures where neither of them existed. So the dig where the trilobites were found has to be at least 3 million years older than the dig where the Ammonites were found. So with that in mind, let's look at the options and see what makes sense.
The rock layers must have formed at the same time because they both contain biozones. * This is nonsense no matter what dates you're speaking of. In effect it claims that all rocks that indicate life were created at the same time. So this is definitely a bad choice.
The rock layers must have formed at different times because they contain two different biozones. * This is technically incorrect since it assumes that all biozones represent an unique period of time which is incorrect. However, since the biozones represented by the presence of Trilobites and Ammonites don't overlap, it is true that these these rock layers were formed at different times. I would have preferred if this option said "non overlapping biozones". But on the balance, I'd consider this option to be true, so it should be selected.
The rock layer containing the trilobites must have formed before the one containing the ammonites. * This is definitely true since the last Trilobite died about 3 million years before the first Ammonite lived. So this is a correct choice.
The rock layer containing the trilobites must have formed after the one containing the ammonites.
* This is the opposite of the previous option. And since the previous option was true, this option must be false. So this is a bad choice
Answer:
Contain standing water
Explanation:
Both lakes and streams vary in size and may contain fresh water. Only streams contain flowing water. Only lakes contain standing water.
There are a few different answers to this question, depending on what you are asking. I'll go over the main ones.
1. The Earth's axis is tilted in comparison to the Sun, so days get shorter in the winter months. This is due to less light, and therefore energy, hitting the Earth directly. Instead, that energy either misses entirely, or hits nearer to the Equator. This is why the poles have twenty-four hour days and nights depending on the season. (Night in the winter, day in the summer.)
2. In terms of the food chain, energy from the sun is converted to basic sugars by plants in a process known as photosynthesis, inside the plant's cloroplasts. Small animals such as mice and insects consume the plants, and the energy those plants converted from sunlight. This continues up the food chain until you get to apex-predators (tigers, bears, wolves, owls, etcetera).
3. In terms of electricity, solar panels are made of tons of 'solar cells' which tend to be lots of silicon atoms, which like to share electrons, and a conductive backing. (Pardon me if some of this section is incorrect, I only have a basic understanding of solar panels) When a photon (that is, a light particle) hits the silicon, it bumps off an electron, and the conductive backing catches it, resulting in a electrical current. This current is incredibly small per solar cell, so you need a ton of them to make any sort of useful power out of them. Solar panels do degrade over time, but incredibly slowly, there are some from the 1970's that still generate just as much power as they did originally (if not, only ever so slightly less).
I hope I answered what you needed to know! If you wanted a different answer, feel free to comment with some clarification and I would love to fill you in :)
Long day typically means warmer days short days typically means colder days
