an f开头的单词

例句：

Aspirin is a mild analgesic.

阿司匹林是药性平和的'止痛药。

Lipotropin is a potent analgesic.

促脂素是一种有效的镇痛药。

The closest living analogue might be a sponge.

现存的最接近的类似物或许是海绵。

He tried to analyse his feelings.

他试图分析自己的感情。