Cannot grab and drag imported audio files

I do not use any other Adobe product, and an just beginning to learn Ch, but already I am stuck!

After importing my own Digital Performer audio song files

(I've tried: aif, wav or mp3's) from my MacBookPro desktop.

My curser cannot grab and drag those imported audio files

from Project or Properties boxes, down to Timeline box. 

Thanks for your help.

DP