The answers are DNA and Nucleus
Well, obviously one would need to start off with a plan. After having an idea/blueprint of what your ideal treehouse will look like try finding some measurements for the wood (or whatever material you will use I won't judge) of course you better already have the length, width, and height of your treehouse. After that, you can get building; which could take days or even weeks depending on the house design and the amount of people you have to help out. Once that's done you can paint and decorate it all you want. (of course, to get it in the tree you might need a pulley to put it up there or build the bottom up on the tree.) And all your missing your ladder and that's it.
The statement that best describes ecological succession is that it always occurs in a predictable pattern. The process is also slow. The correct answer is C.
Because of the way builds up in your body
You can use refraction which is the bending of light through a transparent material. Also the freezing and boiling points of water. One last one is the Cartesian five experiment, this shows the density of water. Hope this helped.
