SSC CGL 12 Jun 2019 Shift 2 Paper

Two statements are given, followed by three conclusions numbered I, II and III. Assuming the statements to be true, even if they seem to be at variance with commonly known facts, decide which of the conclusions logically follow (s) from the statements.
Statements:
All postcard are envelopes.
No envelope is a paper.
Conclusions:
I. Some envelopes are postcards.
II. No paper is an envelope.
III. No postcard is a paper.