Answer:
Predator-prey relationship
Explanation:
A predator prey relationship is one in which interactions usually with consequential effects occurs between two different species. One species usually feed on the other. The species being fed on are the prey while the species being fed is the predator. In this context, the prey is the ant and the predator s are the ant lions.
Answer is Middle Paleozoic era.
Paleozoic era was in 542 Ma - 245 Ma and it has 6 periods as Cambrian, Ordovician, Silurian, Devonian, Carboniferous and Permian.
360-280 Ma - forming of vascular plants with woody tissues, seeds and veins.
430 - 410 Ma - forming of jawed fishes and first amphibians.
420 Ma - forming of scorpions
360 Ma - forming of crustaceans.
Answer: B. Closed
In a closed circulatory system is the one in which the blood is circulated to all the parts of the body of the organism through vessels of different length and width. In this system the blood is pumped from the heart through blood vessels where it is transported to different organs and cells of the body instead of filling up the body cavity.
The answer would be 12 hope this helped