经过一番努力后，坎贝尔了解到他的平均时速是299英里，大感失望。

After his attempt, Campbell was disappointed to learn that his average speed had been 299 miles per hour.

youdao

经过一番努力后，坎贝尔了解到他的平均时速是299英里，大感失望。

After his attempt, Campbell was disappointed to learn that his average speed had been 299 miles per hour.

youdao