1. 申请（Request or ask for something formally）

– I need to ap for a visa to travel to that country.

我需要申请那个的签证去旅行。

– She applied for a job at the local hospital.

她在当地医院申请了一份工作。

– The university will begin accepting applications for the next academic year in January.

大学将在一月份开始接受下一学年的申请。

2. 应用（Use or put something to use）

– Please ap sunscreen before going out in the sun.

在阳光下外出之前，请涂抹防晒霜。

– We need to ap the latest technology to improve our production process.

我们需要应用最新的技术来改善我们的生产流程。

– The principle of gravity applies to all objects, regardless of their size.

重力原理适用于所有物体，无论其大小。

3. 适用于（Be suitable for or relevant to）

– The discount applies to all full-time students.

这个折扣适用于所有全日制学生。

– These rules do not ap to members of the staff.

这些规则不适用于员工。

– The principles of fairness and equality ap to all aspects of our society.

公平和平等的原则适用于我们社会的各个方面。

4. 涂抹（Spread or put something on a surface）

– Ap a thin layer of paint to the wooden surface before varnishing it.

在上清漆之前，先在木面上涂上一层薄薄的油漆。

– She applied a coat of varnish to protect the wood from moisture.

她涂了一层清漆来保护木材免受潮湿。

– The doctor instructed me to ap the ointment to the wound twice a day.

医生指示我每天两次涂抹这种膏到伤口上。

这些是 “ap” 在英语中的四种主要用法，每种用法都有其特定的语境和含义。