The blood has low oxygen content
ANSWER:
I think it's the second one.
EXPLANATION:
in primary succession newly exposed or newly formed rock is colonized by living things for the first time. in secondary succession an area that was previously occupied by living things is disturbed, then recolonizeed following the disturbance.
The answer is C Heterozygous
Explanation: the inability to roll your tongue is a recessive trait. Since both parents are heterozygous, they carry that recessive gene, so their child will have a 25% chance of having that recessive trait; and therefore, unable to roll their tongue.
Answer: The answer would be A;electron probe X-ray microanalysis
I hope that this helps! :D