Answer:
Number of bacteria required 
Explanation:
Given -
Size of each bacterium
micrometers long
These bacteria are arranged end to end.
The size of chain to be formed is equal to
centimetres
Let us say that in forming a chain of
centimetres nearly X number of individual bacterium are required.
hence, number of bacterium required to form
centimetres chain can be represented as

Number of bacteria required 
Answer:
3) 0.75m/s
Explanation:
The wavelength of a wave is calculated using the formula;
λ = v/f
Where!
λ = wavelength of wave (m)
v = velocity or speed (m/s)
f = frequency of wave (Hz)
According to this question, one end of a rope is vibrated to produce a wave with a wavelength (λ) of 0.25 m and frequency (f) of 3.0 Hz.
Using λ = v/f
v = λ × f
v = 0.25 × 3
v = 0.75m/s.
Well he looked at the contents and saw they some of them had similar shapes so
Answer:
Cnidarians represent a more complex level of organization than Porifera. They possess outer and inner tissue layers that sandwich a noncellular mesoglea. Cnidarians possess a well-formed digestive system and carry out extracellular digestion.
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All you would have to do is sum them up cause their going the same direction.