Answer:the first one is external stimulus
And the second one is migration
Explanation:
The spread began in the 7th to 9th century, originally brought to North Africa under the Umayyad Dynasty. Trade networks were extensive, spanning through north and west Africa which created a medium in which islam peacefully spread through the merchant class.
I think your answer is B.) The objects must be in direct contact with one another
Answer:
Radiometric dating of basalt on the ocean floor provide us with an absolute age for the planet earth because the oceanic crust is recycled too frequently at subduction zones,
Explanation:
Radiometric dating of basalt on the ocean floor can not provide us the absolute age of the planet earth due to the subduction. In the process of subduction oceanic plate went below the continental plate as it is less denser. It then melts there and its recycling takes place frequently. So the radiometric dating of basalt on oceanic plate can not provide us the true information regarding the age of the earth.
