dodder|doddered|doddering

花园里的向日葵被黄丝状的菟丝子缠住了。

The sunflowers in the garden were tangled with yellow ___dodder.

老人走路时双腿因年迈而颤抖。

The old man's legs ___doddered with age as he walked.

那位颤颤巍巍的老太太拄着拐杖慢慢走着。

The ___doddering old woman walked slowly with her cane.