n.颤声；颤音；啭声
v.用颤声发声；发某字母的颤音
A trill is a rapid alternation between the two notes. 颤音是两个音符之间的一种快速转换。
This is a letter with a trill. 这是个发颤音的字母。
The canary was trilling away in its cage. 那只金丝雀在笼中鸣啾。
Can you trill the sound as in Spanish? 你能以颤音发出西班牙语中的音吗?
