particle
n
1 very small bit or piece (of sth) 微粒; 粒子
particles of dust/dust particles 尘埃
He choked on a particle of food. 他让一小粒食物噎住了.
2 smallest possible amount 极少量
There's not a particle of truth in her story. 她讲的没有一句实话.
3 (also ad,verbial `particle) (grammar) word (eg away, back, down) used esp after a verb to show position, direction of movement, etc 副词小词(如away、 back、 down, 尤用於动词後, 表示位置、 运动方向等)
In `break down' and `tell sb off', `down' and `off' are adverbial particles. 在break down和tell sb off两词组中, down和off都是副词小词.
I suggest that we ask users of this machine what they think about it. We can photograph them using it too. Then we can put their comments at the top of the advertisement in big print. We can bring in some humour too. People enjoy reading humorous ads.