tā / zuò / shí / yàn / shí / máo / shǒu / máo / jiǎo / yí / bù / xiǎo / xīn / dǎ / suì / le / shì / guǎn

他做实验时毛手毛脚，一不小心打碎了试管。

He was careless and clumsy during the experiment and accidentally broke a test tube.