Question

do they do their work regularly change to passive voice​

Answer 1

We make simple future tense forms by putting will / shall before the base form (infinitive) of the verb. If the sentence in the active voice consists of an object, we can change it into the passive. In the example sentences given above, the first one has an object (the job). We can convert it into the passive voice.

Answer 2

their work is done by them. regularly