问题
选择题
They have________signs in some places to remind (提醒)the visitors not to step on the grass.
A．put on
B．put up
C．put down
D．put out
答案
答案：B
答案 B [句意：他们已在一些地区张贴标志，来提醒游客不要踏草坪。put on穿上；put up张贴；put down放下；put out扑灭。]