Select the most appropriate option to fill in blank No. 1.
Show answer & explanation
Correct answer: C
Explanation
The correct answer is option 3 i.e. major.
Context: The sentence says transportation is a big cause of environmental pollution. The correct word should emphasize its importance or seriousness as a source.
Meaning of the words:
Different: means not the same, which does not fit here.
Cautious: means careful, not related to pollution.
Major: means very important, significant, or large in amount.
Rare: means uncommon or unusual, the opposite of what the sentence intends.
Correct word: Major
Reason: Transportation is indeed one of the major sources of pollution, mainly because of CO2 emissions. Other options do not match the idea of size or importance.
Final Sentence: Transportation is a major source of environmental pollution, mainly due to fossil fuel-powered vehicles emitting CO2 into the atmosphere.
Hence, the chosen option is correct.