The people in Ya'an have met lots of difficulties, but they haven't ________ hope.
A:picked up
B:given up
C:looked for
D:waited for
每年的9月22日为“世界无车日”,我国承诺开展无车日活动的城市越来越多。开展“无车日”活动( )
K是自然数,且1001×1002×2014×2015K是整数,则K最大是____ .