Answer:
Id say its B or D but dont take my word for it
Explanation:
The answer is True, i think there are about 700
The appropriate answer is doing. All of the above. Heavy metals are sometimes used in agricultural chemicals and can contaminate both terrestrial and aquatic ecosystems. Heavy metal concentrations can build up overtime as industrialization progressed. Chemical spills can introduce heavy metals to ecosystems quickly with devastating effects.
Answer:
During depolarization, the membrane potential rapidly shifts from negative to positive. As the sodium ions rush back into the cell, they add positive charge to the cell interior, and change the membrane potential from negative to positive.
Explanation:
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.