单选题 What should be done to prevent insects from eating into the water harvesting system at the bottom?

A、 The two bags holding the water should be put inside the metal tank.
B、 The inner bags need to be replaced every two years.
C、 The water harvesting system should be built on a platform.
D、 A cover should be used to prevent insects from eating it.

【正确答案】 C

【答案解析】最后一段第一句International Development Enterprises says the water harvesting system should be built on a raised structure to prevent insects from eating into it at the bottom。国际开发企业称雨水贮存系统应该建在一个高起的平台上以防止昆虫咬穿底部进入系统，选C。