Questions for aircraft experts

[ccc]

Wonder if somebody could give me the answers, pliz take a close look at "drop tanks" on mig17/19:
http://www.fas.org/nuke/guide/russia/airdef/mig-17.htm http://www.fas.org/nuke/guide/russia/airdef/mig-19.htm

1. these drop tanks are hang under mainwing, with a plyon and TWO sturts. are these parts jettisonable?? or they are fixed before taking off, and can only be removed after them returning home?

2. if these tanks are jettisonable, when dropped, will pylon part be dropped as well?
the two sturts?