source: Saint Martin is a tropical island in the northeast Caribbean, approximately 300 km (186 miles) east of Puerto Rico.
target: Saint Martin, a tropical island in the Caribbean, is about 300 km east of Puerto Rico.
references: Saint Martin, a tropical island in the Caribbean, is about 300 km east of Puerto Rico. Saint Martin is a tropical island. It's in the northeast area of the Caribbean. It is 300km (186 miles) east of Puerto Rico. Saint Martin is an island located in the Caribbean, 300 km east of Puerto Rico. Saint Martin is a tropical island in the northeast part of the Caribbean which is located around 300 km (186 miles) east of Puerto Rico. Saint Martin is a tropical island in the northeast Caribbean.  It is approximately 300 km (186 miles) east of Puerto Rico. Saint Martin is a tropical island in the Caribbean, approximately 300 km east of Puerto Rico. Saint Martin is an island in the Caribbean. It is located 300 kilometers east of Puerto Rico. Saint Martin is a tropical island in the northeast Caribbean. It is approximately 300 km (186 miles) east of Puerto Rico. Saint Martin is an island located in the Caribbean 186 miles east of Puerto Rico. Saint Martin is an island in northeast Caribbean about 300 km (186 miles) east of Puerto Rico.