他的工作效率很高。
他精通游泳。
It is designed for those already proficient at the First Series.
它是专门为那些已经熟练的第一系列。
There are simple ways to train people to become more comfortable and proficient at it.
有一些比较简单的训练办法，可以让人们在提问时更自在，也更娴熟。
They are professional in business, proficient in foreign languages and good at management.
他们是专业的业务人员，精通外语和善于管理。
At least proficient in a foreign language.
至少熟练运用一门外语。
At least proficient in a foreign language.
至少熟练运用一门外语。
应用推荐