D, curving waves.
Waves can’t actually curve in nature, therefore it’s a metaphor
Answer:
The title "two kinds" may refer to two kinds of whatever is emphasized in the piece of writing you are asking about.
The correct answer is letter A. DNA. It is the <span>cellular component that increases in the salivary gland cells as the silk proteins are synthesized. Though the amount of DNA that is in the cells remains constant thus it will not increase for silk protein production. Because of the increased mRNA the is copied from DNA, then it facilitates and enhances the protein translation process.</span>
