Add punctuation: With its myriad of small scented flowers and fresh green foliage Persian violet is hard to resist
A: With its myriad of small, scented flowers and fresh, green foliage, Persian violet is hard to resist.

Add punctuation: He could not compute
A: He could not compute.

Add punctuation: The more generations that are tested the higher the probability for breeding away from the diseases will be
A:
The more generations that are tested, the higher the probability for breeding away from the diseases will be.