Ijust looked up the instruction for seat height, basically, the heightshould be set where baby can touch the bottom with a flat foot using astraight leg. For more info, see page 19 of the instruction booklet.
http://www.gracobaby.com/assets/pdfs/instructions/ISPE020AA.pdf page 19.
没说清楚,我记得会站之前应该是可以踮脚站,不过不能让他自己支撑自己。