a grain of rice

基本解释

So small 1, 000 could fit on a grain of rice. And it's 3D.
一粒大米上可以放一千个这样的小地图，而且还是3D的。
Working together for the first time in 2002, they chose the theme of chopsticks as, whether picking up a grain of rice or a more sizeable morsel of food, two chopsticks are essential .
两位艺术家第一次合作是2002年，为在纽约前波画廊的首次合展《筷子》创作，他们选择了筷子作为主题，因为在中国无论是夹一粒米饭还是一块大的食物，两根筷子总是必不可少的。
An average Chinese can very easily pick up a single tiny grain of rice， or a tiny piece of peas， or a slippery button mushroom or sea cucumber.//
中国人一般都能随心所欲的用筷子夹起一粒米饭，一粒豌豆，一只滑溜溜的蘑菇或海参。

Since 2008 the United States has not sold a single grain of rice to Cuba.
The Philippines this week said it is cutting rice imports because of high prices, even though the country lost more than a million tons of grain to typhoons this year.

Anytime a black-eyed pea meets a grain of rice, it becomes Hoppin' John.
NPR: Vertamae's Hoppin' John
The ultrasound generator used in this technique can focus its energy into a space about the size of a grain of rice.
ECONOMIST: Thermal treatments of cancer are remarkably effective