题目选项分析

Dengue fever, a viral disease, is common in humid, tropical climates, and it has become more prevalent as flooding has expanded the habitat of mosquitoes which become the virus’s carriers for much of its life cycles.

Dengue fever, a viral disease, is common in humid, tropical climates, and it has become more prevalent as flooding has expanded the habitat of the mosquitoes that are the virus’s carriers for much of its life cycle.