"All of a sudden..." is a transition that shows suspense. It says something happened, but it didn't happen with any warning and it doesn't tell the reader up front what went on or if it was good or bad.
The answer is B: Less than a decade ago, the HSUS...an affiliate [Human Society International].
Brackets are used to give the writers (when they need to add information) an opportunity to add an explanation, or emphasis to a word, or change a <em>quote to fit to a sentence, but without changing the meaning of the text</em>. In A) <em>global work</em> doesn't need explanation; C) <em>decade</em> doesn't need explanation; D) <em>HSUS</em> was already explained in the first sentence of the text.
Umm.. Any site ending in .Gov or .Edu
Encyclopedia
Books written in depth on the subject
Any written or spoken words from creditable people who study\mastered the subject
Hope this helps.
Answer:
A.It takes a lot of different tools to fight disease.
B.Modern technology is an important part of the fight against disease.
D.Different types of scientists use different tools to fight disease.
Explanation:
He compares it to sleeping flowers
