1. 两年一次的：98.biannual一年两度的 | biennial两年一次的 | 99.chord琴弦

2. 二年生的：bicapsular 二蒴果的 | biennial 二年生的 | biennial fodder crop 二年生饲料罪

3. 每两年的：bi-两,双 | biennial每两年的 | bilingual会说两语言的

1. 两年一次的
A biennial event happens or is done once every two years.

e.g. ...the biennial Commonwealth conference.
两年一届的英联邦会议

2. 二年生植物
A biennial is a plant that lives for two years. It flowers, produces seed, and dies in its second year.

noun

1. (botany) a plant having a life cycle that normally takes two seasons from germination to death to complete
flowering biennials usually bloom and fruit in the second season