Answer:
nitrogen that cannot be used
Answer: a star expels most of its outer material until only the hot core remains, which then settles down to become a young a white dwarf
Explanation:
Answer:
If two breaks occur in one chromosome, sometimes the region between the breaks rotates 180 degrees before rejoining with the two end fragments. Such an event creates a chromosomal mutation called an inversion.
Answer:
There is no enough data on Earth's temperature before life appeared.
Explanation: