■ part of

part of 前面不用 a。

• Part of what I'm searching for is a reason for that slowing.我正在查找的问题当中，一部分就是要弄清楚进度因为什么原因慢了下来。

• rise
• rise
• river
• road
• rob
• room
• royal road
• rubbish
• rule
• rule out
• 's
• safe
• safety
• sailor
• salary
• salary
• salary, wage 与 pay
• sale
• same
• sanguinary
• sanguinary 与 sanguine
• sanguine
• save
• saving
• say