Answer:
the sing post
Explanation:
because the reference frame is a fixed object that determines whether a body is in motion or not so the other passengers are fixed but relative to the the the man is at rest but relative to the sign post it is in the motion, did I get me, sister
Answer: The strength of an acid or alkali depends on the degree of dissociation of the acid or alkali in water. The degree of dissociation measures the percentage of acid molecules that ionise when dissolved in water. He could use universal indicators or litmus paper for this.
i hope this helps you!
A simply because of I'm a pretty good guesser, Hope this helps.