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 correct answer is : D. She uses images of the globe and the Yangtse River to represent the narrator's feelings.
#8. the first sentence
#9. the first sentence
#10. 'Wonder' by R. J. Palacio and 'The Hunger Games' by Suzanne Collins
do u need the summary too?