In They have it, have is a full verb, but in They have done it, it's an auxiliary verb.

Light relief is given by the carelessly happy and guiltfree (because unmarried) lovers Varvara (Barbara Walker) and Vanya (Paul Crook)...

It is assumed that a general mixed state ρ is given in the sector A and the problem is to “send it” to the spacely separated sector C.

Going back to the nine to five after the weekend can be depressing.