Because your Teeth are composed of calcium, phosphorus, and other minerals. ... But bones are still not as strong as teeth. The hardest part of the human body ,teeth mostly consist of a calcified tissue called dentine. The tooth's dentine tissue is covered in enamel, that hard, shiny layer that you brush.
Using the significant figure it would be 27.3
Reaction:

Magnesium is a stronger reducing agent than copper and is thus able to reduce copper(II) oxide.
Products of the reaction: Magnesium oxide and metallic copper.
Answer:
True
Explanation:
The first artificial use of a PGR was to stimulate the production of flowers on pineapple plants. They are now used widely in agriculture. Plant hormones are also used in turf management to reduce the need to mow, to suppress seedheads, and to suppress other types of grass.
I believe the answer is A. <span>make a softer sound because the shark will not hear the softer signal.
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I say this becasue "</span><span>Some of the sounds dolphins make are outside the range of human hearing." So that means the the dolphins speak at a higher wavelength then us humans and we can't hear it so they could use that to their advantage and speak at a height wavelength to each other when sharks are near.
I could be wrong, but I think the answer is A. </span>