One important reason we do not know much about the geologic history of the Precambrian is that ________
A) the climate was so harsh that erosion removed most of the rocks that formed during the Precambrian.
B) rocks did not exist during much of that time
C) radioactivity was not measurable during the Precambrian
D) there are very few fossils preserved in Precambrian rocks
E) we have not yet been able to establish the half-lives for radioactive elements that existed in the Precambrian
D
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Markets are the only means through which decisions are made to hire people, use land, etc
Indicate whether the statement is true or false
The jet stream that forms in summer near the tropopause above Southeast Asia, India, and Africa is known as the ____ jet stream
a. polar-front b. tropical easterly c. noctural d. stratospheric polar night e. low-level
Intense tropical cyclones with winds above 109 kph are called hurricanes, typhoons, or cyclones, depending on the part of the world where they form
Indicate whether the statement is true or false
Which of the following statements about malaria is true?
A) Malaria is the greatest health threat to northern Eurasia and North America. B) Mosquito saliva transmits tiny sporozooites to the victim when they are bitten. C) The organism that causes malaria is a virus related to H5N1. D) Malaria can be transmitted to humans by contact with pig or bird feces.