在市场经济活动中，为了获取利益，可以采取各种手段，与同行竞争。
参考答案：错
Do you like lettuce ______ sandwiches? [ ]
A. of
B. in
C. at
D. with
When fighting a fire on a bulkhead using a portable carbon dioxide extinguisher，the stream should be directed at the（）.
A.base of the flames，moving the horn from side to side，following the flames upward as they diminish
B.top of the flaming area，moving the horn from side to side，following the flames downward as they diminish
C.center of the flaming area，moving the horn vertically from top to bottom
D.bottom of the flaming area，moving the horn vertically to the top following the flames upward as they diminish
