第012句

One of the responsibilities of the Coast Guard is to make sure that all ships dutifully follow traffic rules in busy harbors.

译文：海岸警卫队的职责之一是：确保所有船只在繁忙的港口严格遵守进出港规则。

点睛：句子的主语为one，而非responsibilities或Coast Guard．因此系动词用is。that引导的是make sure的宾语从句，其中dutifully为follow的状语，意为“尽职地”。