Question

A newly released study on the tectonic plates forming the Pacific basin indicates that by the time they had shifted even a few miles, a vast percentage of the coastline which is currently home to major world cities, because of global warming, will have already become entirely submerged.

• A. by the time they had shifted even a few miles, a vast percentage of the coastline which is currently home to major world cities, because of global warming, will have already become entirely submerged
• B. by the time they shift even a few miles, a vast percentage of the coastline, which is currently a home of the major world cities, will have already become entirely submerged due to global warming
• C. by the time they have shifted even a few miles, a vast percentage of the coastline currently home to major world cities already will have become entirely submerged because of global warming
• D. a vast percentage of the coastline that is currently home to major world cities will have already become entirely submerged due to global warming by the time they have shifted even a few miles
• E. a vast percentage of the coastline that is currently home to major world cities, by the time the plates have shifted even a few miles, will become entirely submerged because of global warming

Answer 1

The correct option is C by the time they have shifted even a few miles, a vast percentage of the coastline currently home to major world cities already will have become entirely submerged because of global warming

A. 'had shifted' is a tense error.

B. 'home of' is idiom error

C. avoids the tense, idiom and altered intent pitfalls.

D. altered intent due to wrong word order. The choice suggests that the cities have shifted a few miles rather than the plates have.

E Altered intent due to wrong word orders. The choice says that the plates will have submerged rather than the cities will have.