herd
n. a group of people,crowd
private
adj.personal, not public
bleachers
n.a usually uncovered stand of tiered planks providing seating for spectators
straggle
v.to wander from the direct course or way : rove, stray
cautious
adj.careful about avoiding danger or risk
grin
n./v. smile
perpendicular
adj.vertical
blister
n.水泡
vcatch sight of
v. see
graze
v.to feed on
in unison
in perfect agreement
collapse
to break down completely