Mark the letter A, B, C, or D to indicate the sentence that best combines each pair of sentences in the following questions.
Question. Wastewater is treated and turned into drinking water. This is done to ensure there is no shortage of fresh water.
A. For there is shortage of fresh water, wastewater is treated and turned into drinking water.
B. Wastewater is treated and turned into drinking water because there is shortage of fresh water.
C. Wastewater is treated and turned into drinking water though there is no shortage of fresh water.
D. To ensure there is no shortage of fresh water, wastewater is treated and turned into drinking water.
Đáp án D
Dịch: Để đảm bảo không thiếu nước ngọt, nước thải được xử lý và biến thành nước uống.