题目选项分析

Whereas the use of synthetic fertilizers has greatly expanded agricultural productivity in many parts of the world, an increase in their use can create serious environmental problems such as water pollution, and their substitution for more traditional fertilizers may accelerate soil structure deterioration and soil erosion.

Whereas the use of synthetic fertilizers has greatly expanded agricultural productivity in many parts of the world, if these fertilizers are used increasingly, they can create serious environmental problems such as water pollution, and if used as substitutions for more traditional fertilizers, they may accelerate soil structure deterioration and soil erosion.