Topic: Student has a VERY slow trill - how do I improve it?

Dear all,

My bassoon student has been playing for 2 years, exclusively under my tutelage.  His trill is very slow - more like sixteenths (if that).  Even with the strong fingers of his dominant hand, it is very slow.  Any idea how best may I improve that?

Wai Kit Leung

oboe (French, Viennese, baroque), bassoon (German, French, baroque), shawm, dulcian