D. Oxygen and metal
They usually contain some form of metallic cation, given that carbonates are the most distributed minerals in the Earth's crust.
Hope this helped!
Answer:
The missing word is things.
However, the real question is how one material can serve so many purposes? That is what makes it possible for the spiders web to have a high "utility" value?
The answer is in how the spiders make the silk.
Explanation:
So it interesting to note that spiders do not make only one kind of silk. They vary depending on what purpose it's doing serve.
The most common type is Dragline Silk.
Dragline Silk: This contains spidroins. Spidroins fall under a category of a protein called scleroproteins. Because of its composition, a strand or fiber of Dragline has the same tensile strength as steel albeit more flexible. That is if one produced steel the diameter of a spider's silk, and compared both for strength, the silk will be stronger.
The spider produces Dragline silk in its silk glands where they are as viscous as a paste. From here is pulled out or extruded into lines of silk.
Other types of spider silk are:
- Capture-spiral silk. Also known as the Flagelliform, they are used for securing lines of the web. They are adhesive, very elastic, and possess high tensile strength.
- Tubiliform silk: They are also called Cylindriform. Its main use is for the protection of spider eggs. It is used to make a sac for which protects eggs. This type of silk is the toughest.
- Aciniform silk: For preserving fresh prey.
- Minor-ampullate silk: This type is used by spiders for creating temporary support while they are spinning a web. Etc.
Cheers
There are many environmental negative direct outcomes of unused excess nitrogen from nitrogenous fertilizers. One of these is eutrophication. Eutrophication is the excessive richness of nutrients in a water body as a result of fertilizer run offs from the land, which causes a dense growth of plants in the water. Other negative outcomes are: green house effects, acid rain and contamination of underground water which has negative effects on human health.
I believe the answer to this is B
The feature of the bone tissue which allows it to normally withstand lateral stress without it giving or breaking up. Because the bone which receives the most impact, each opposite side stretches, and last but not the least bones are able to cancel them out themselves.
