The first line of defence (or outside defence system) includes physical and chemical barriers that are always ready and prepared to defend the body from infection. These include your skin, tears, mucus, cilia, stomach acid, urine flow, 'friendly' bacteria and white blood cells called neutrophils.
First eliminate choices C and D since they both mention that fact 1 is crossing over ( which is also referred to as genetic recombination) . So you're left with A and B and the correct answer is B .
You would expect an earthworm to have no exoskeleton because as you see it is very flexible and soft. Organisms with such have body parts that are divided and an earthworm do not have any visible parts on them also having an exoskeleton would not allow an organism to move like an earthworm does.
Humans caused damaged by all the pollution in the earth atmosphere with is making global warming it changes by how much pullution is going into the atmosphere
A watt IS by definition a J/s so and so an 18000 W station will use 18000 J/s so it is C
