Focus on mrs birling duh i think thats the awnser
Answer:
Word choice affects the tone, imagery, and voice of a written piece. Just as you use your tone of voice to demonstrate to others how you feel, in writing you use your words to communicate your attitude toward a subject. Tone can be positive or negative, happy or sad, angry or peaceful, hopeful or desperate, and so on.
Explanation:
Um i think your forgot to add part of the question
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