Answer:
Due to presence at early days of the planet.
Explanation:
We only find the remains of single celled organisms in the oldest fossils because the single celled organisms are the organisms that were present in the early days of this planet. These single celled microbes were present about 3.7 billion years ago while on the other hand, the oldest rocks are only a little older i. e. 3.8 billion years so these single celled organisms are considered as oldest fossils on this planet.
Answer:
7) a. Absorbed: black surfaces absorb light, like in a playground.
b. Transmitted: when light falls on transparent objects, it is transmitted, goes straight through the object, like the clear glass of a window
c. Reflected: when light falls on a smooth, shiny object, it bounces off in one particular direction, like looking at the smooth surface of a lake