Question

why is it necessary to sterilize the roots of rhizobia in the experiment?
a) to prevent the destruction of rhizobia
b)to prevent the bacterial infection to us
c)to prevent the mixing of other bacteria with rhizobia
d)none of these

Answer 1

mammary glands of mammals. All mammals, including humans, will normally produce milk to feed their offspring until they are ready for solid food.

It contains valuable nutrients, and it can offer a range of health benefits. Calcium, for example, can prevent osteoporosis.

However, some people are not able to digest lactose, the sugar in milk, after they are weaned, because they do not produce enough of an enzyme known as lactase. Lactase is needed to digest milk properly.

As concerns about lactose intolerance and milk allergies widen, a range of substitute milks, such as almond and soy milk, have become available.