Picolinic acid
[建] 啶甲酸-[2]
🧩 词语组成解析
🗣️ 情景例句
To advertise during prime time TV is very expensive.
在电视的黄金时段买广告是很贵的。
The chemist is testing enzymes.
化学家在试验着酶。
But a watch could never repair itself----it does not consist of living parts,
但是，手表决不会自行修理，它不是由有生命的部件组成，