The correct answer is - 45 percent.
Since the clock produces 45 useful unites energy units for every 100 unites of energy that it uses, than it turns out that the efficiency of the clock is 45 percent.
It's being estimated that dinosaurs lived on Earth from about 237 million years ago to about 66 million years ago. So answers B and D are definately too "old", while answer A is too "young". I'd pick answer C as it's most probable.
Answer:
They maintained good farmland by managing the rivers.
Explanation:
because I just took the test hope this helps
I would take the advancement of the refrigeration as a crucial part in the increasing of the production.
The refrigeration has been extremely important in the agriculture and the amount of production in it, because with it the agricultural products can be kept fresh for much longer periods. Because the products can be kept fresh for much longer time, that means that they can be delivered to pretty much every part of the world and not be spoiled. So the refrigeration opened up the doors for the farmers in the sense that instead producing only for the region or the country they live in, they can now produce much more for exporting, as the products will not spoil and remain fresh. That has also brought in much bigger profit for the farmers, and the production is constantly increasing because the whole market in the world is open with this technological advancement.
