Drought. Hope that helps.
Answer:
Paleozoic
Explanation:
The first insect fossils are dated to the Devonian, but because of the development of the genetics, the scientists have been able to trace the appearance of the first insects in the Ordovician. The insects originated from the crustaceans. Initially they were walking on land, but they hadn't developed wings. The wings came to develop in some insects in the Devonian, and since than it has gradually became one of their trademark features. It is interesting that the first insects actually appeared at the same time with the first terrestrial plants, and also that they are the first organisms to develop wings and be able to fly.
It is B, <span>In fact, water will sink as it cools until a certain point. If I recall correctly this is around 39 F. As the temp gets lower than that water actually begins to expand and becomes less dense. This is why ice floats, which we should all be thankful for. If ice didn't float than all water on earth would likely freeze solid and life would have probably never evolved past small single celled things.</span>
The U.S economy produce 20% of the world's output
Below I have included an image that has the measure of all of the angles on it.
We can find the measures of the angles here due to the laws about complimentary angles. A pair of complimentary angles can be formed when 2 lines are perpendicular, and when added together, will always equal 90. The pair are the angles that are not directly adjacent from each other. In this figure, "x" and "(4x-10)" are a pair. According to another law, opposite angles, or adjacent angles, will always be equal to each other. Using the logic above is how we can find the measure of all angles.
Since one angle has a box, we know the lines are perpendicular, and that the laws of complimentary angles apply. We can also use that to see that the angle diagonal from it is equal to 90.
To solve for the other measures, we need to add the 2 equations together and set them equal to 90 (because of that law we talked about before).
x+(4x-10)=90
5x-10=90
+10+10
5x=100
/5 /5
x=20
Now that we know x equals 20, we can substitute that value in and solve.
x=20
=(4x-10)
=(4*20-10)
=(80-10)
=70
We also know this is correct because 20 and 70 equal 90.