What is the difference between an index and a glossary

Need some ! asap i need to figure out 3 major changes in bridges over time and why these changes to adapt to both improvements in technology and changing social links would also alot.

Which is the most challenging aspect of developing a screenplay? finding an original idea collaborating with a script doctor establishing the key elements of plot selling a finished screenplay

Pls! choice of medium allows the artist to a.convey different messages.b.experiment with combining materials to create new media.c.reconnect with old forms of art.d.improve realism in art, particularly with portraits.