Answer:
True.
In pre-colonial Africa, some primitive versions of government systems were used.
<u>Answer:</u>
All of the above mentioned options can be used by scientists to date the sediment layer they are found in.
<u>Explanation:</u>
- Rock fossils, animal fossils, etc.found in the sediment layer can be used to determine the age of the sediment based on the period of the existence of that animal or the period of formation of the rock.
- Tree rings clearly exhibit the age of the tree. Hence, a sediment layer with the evidence of tree rings can tell the age of the sediment layer.
- An amalgamation of the data obtained from the animal growth rings and the period of existence of that specific animal species can be used to calculate the age of the sediment.
- The intensity of radioactivity left in the isotopes clarifies how old the isotope is.
- The age of mineral elements can be determined exactly with the help of processes like Potassium-Argon dating, Uranium-Lead dating, etc.
- Thus it would be easy to determine the age of the sediment layer containing mineral elements.
Answer:
Poor planning, and disease
Explanation:
The obstacles that the French faced while attempting to build a canal across Panama were diseases and poor planning. The French dealt with constant outbreaks of malaria and yellow fever, which slowed construction and caused the deaths of thousands of workers. The French also did not take into consideration the geographical differences between the Suez Canal region and the Panama region. The French had succeeded in building a canal at sea level in Egypt, and they mistakenly thought a similar design would work in Panama. However, the difference in the Atlantic and Pacific Ocean sea levels, as well as the difference in elevation of the Panamanian terrain, prevented them from building a sea-level canal. The United States knew about these two problems when they undertook the project. They took preventative measures by reducing the disease-spreading mosquito population and using a canal-lock system to overcome the elevation obstacle in Panama.
Answer:
Options (B)
Explanation:
New Zealand is an island country, located adjacent to the great pacific ocean. Whereas, the country of Australia is located towards the north-western side of New Zealand, at a distance of about 2500 miles.
The capital of Australia is Canberra, and the capital of New Zealand is Wellington.
Most of the interior Australia is comprised of desert where there occurs little or no rainfall, whereas there occurs large mountains at the central portion of New Zealand and is mainly due to the presence of active plate margin.
There are about 600 large islands in New Zealand, and majority of its population lives in Aukland, which is located in the extreme northern side of the country.
Thus, the correct statement is option (B).
Answer: b. Orchid mantises tend to be advantaged in habitats that remain constant; the rain forest habitat is likely to shift because of global climate change.
Explanation:
The orchid mantis is a predator in South East Asia that camouflages itself as an orchid to catch its prey.
While the tropical cockroach is a more hardy specie, the optimum habitat for orchid mantises is one with limited variation in temperature, moisture and humidity. Therefore, as temperatures increase and climate change results in severe weather changes, it will lead to adverse effects on orchid mantises.
