Answer:
D. DDT
Explanation:
DDT is highly persistent in the environment means that it break down very slowly in the environment. The half-life for DDT is from 2 to 15 years. Half-life is the time needed for the degradation of half of the compound. Persistent bio-accumulative toxic substances (PBTs) are chemicals that break down slowly in the environment and its accumulation in living organisms are toxic. Some PBTs are dispersed through air currents while some uses other environmental pathways, resulting in contamination of regions far from their points of origin.
Answer:
Newer layers of earth form <u>on</u><u> </u><u>top</u> of older layers, so as we dig, we can see further back in time. Comparing the fossils between the layers can offer evidence of change.
<u>Phyletic</u><u> </u><u>gradualism</u> - slow, but constant gradual change; supported by transitional species in the fossil record
<u>Punctuated</u><u> </u><u>equilibrium</u>- long periods of no change followed by short periods of rapid change. Can also be supported by the fossil record when no transitional species are found.
Answer:
Ectopic pregnancy can cause the burst of fallopian tube. If previous ectopic pregnancy occured then again onset of this type of pregnancy may lead to life threatening bleeding. Having the abdominal surgery before may also proved as a risk.
