介名a t war处于交战状态
in return 作为报答；回报
by design＝on purpose 故意地
on the scene 到场；在场 In return，she received a sense of satisfaction and fulfillment.作为回报，她收获了满足感和成就感。
She arrived just as we were leaving，but I'm not sure whether this was by accident or by design.她刚好在我们正要离开时到达，但我不能肯定这是出于偶然还是有意安排。
介名介 in search of寻找
in return for 作为对……的回报Can I buy you lunch in return for your help?
为了感谢你的帮助，我请你吃午饭好吗？
Ⅰ.[原创]语境填空(填入一个适当的词)
A warehouse 1.belonging (belong) to a chemical factory exploded last night，causing massive damage.Firefighters soon appeared 2.on the scene.Then more rescuers were sent 3.in search of the survivors.There is a debate 4.on the cause of the explosion.Someone suspects that this is 5.by design rather than by accident.Police say