Answer:
A. 1
Explanation:
pH is a measure of how acidic/basic a substance is. The range goes from 0 - 14, with 7 being neutral. pHs of less than 7 indicate acidity, whereas a pH of greater than 7 indicates a base.
note: the closer you are to the neutral the weaker it gets.
An open circulatory system simply
means that the blood flows out of vessels and into the spaces or sinuses. Invertebrates,
insects and crustaceans has an open circulatory system where pump blood goes
into a hemocoel and diffusing back to the circulatory system between cells. In
other animals, the heart pumps the blood into the body cavities, spaces or
sinuses, where the blood surrounds the tissues.
Poliomyelitis or Polio, a virus and viral disease. Poliomyelitis while relatively common and asymptomatic, had a high prevalence of paralysis due to the sheer number of infected. The vaccine was created by Jonas Salk, that immunized the patient towards the disease, saving countless lives, and effectively paved the way to eliminating polio in US.
D:viruses are not killed by antibiotics.
Answer:
In the given case, the most appropriate step to be taken by Brian in order to formulate the hypothesis is to visit other households with cats. In the given case, Brian has to confirm that whether he is allergic to cats or not, and for this, he must go on to find if a similar sneezing reaction is experienced when he is around other cats apart from aunt's cat.
It can be a case that some other environmental elements may have been resulting in the condition. Thus, wearing a mask would not help the cause straightforwardly as it would not confirm that Brian is allergic to cats.
