他似乎对作业感到有些吃力。

He seems to be ___struggling with his homework.

他正在努力通过考试。

He is ___struggling to pass the exam.

小猫被绳子缠住后一直在挣扎。

The kitten kept ___struggling after getting tangled in the string.

两名摔跤选手在擂台上激烈搏斗。

The two wrestlers were ___struggling fiercely in the ring.