Answer:
The difference between a submarine and a submersible is a submarine has enough power to leave port and come back to port under its own power. A submersible has very limited power reserves so it needs a mother ship that can launch it and recover it.A submersible is a small watercraft designed to operate underwater. The term submersible is often used to differentiate from other underwater vessels known as submarines, in that a submarine is a fully autonomous craft, capable of renewing its own power and breathing air, whereas a submersible is usually supported by a surface vessel, platform, shore team or sometimes a larger submarine. In common usage by the general public, however, the word submarine may be used to describe a craft that is by the technical definition actually a submersible. There are many types of submersibles, including both manned and unmanned craft, otherwise known as remotely operated vehicles or ROVs.Submersibles have many uses worldwide, such as oceanography, underwater archaeology, ocean exploration, adventure, equipment maintenance and recovery, and underwater videography.
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
Longitude is when your measuring west of standard of meridian of a celestial object
