Is - two billion dollars is a unit, one unit so it is singular and you use the singular verb
think - scientists is a plural, therefore, you must use the plural verb form of think
The sentence should be like this: Do you like Robert Frost's poem "Stopping by Woods on a Snowy Evening"? So the answer is D. This is true of any proper titles.
Answer:climate change and changing economic is a hard obsticle to face for the Louisiana sugar factory
Explanation:
They built houses to keep the sugar warmer like a green house but for sugar cane instead
