What are sieve tubes made of? to which are companion cells assciated? to what phloem parenchyam are associated? to what pholoem fiberes are asscioiated?

What are sieve tubes made of? to which are companion cells assciated

1.	What are sieve tubes made of? to which are companion cells assciated? to what phloem parenchyam are associated? to what pholoem fiberes are asscioiated?
Answer» When the amplitude of the PENDULUM is larger, there is a SLIGHT increase in the period, but not in any significant WAY. ... There are only TWO things that can change the period of a simple pendulum: the length (L) of the string or rod and the VALUE of the acceleration due to gravity