Femtogram
毫微微克(10的-15次方克)
??? 情景例句
Retired and moved to New York
我退休了， 搬到紐約
Sorrow comes unsent for.
悲哀來時(shí)不須邀。
What is the most popular food in the USA? I think it is fried chicken.
在美國(guó)什么食品最受歡迎呢？我認(rèn)為是炸雞。