translation exercises

You could try contacting the technical team about this (via Tools -> Help and Support -> dropdown menu) but this is a bugbear for me as well. If you get a sentence wrong in the Writing exercises, the answer page is often rich in alternative ways to translate it. You can review previous questions during or at the end of the exercise by flipping to the previous pages (or at least you can on an iPad ) but apart from taking screenshots of individual answers there doesn’t seem to be a way of reviewing them later.

Isn't that already the case in the writing exercises on kwiziq?

It's difficult to realize this in practice because each sentence in English has many equally possible and correct correspondences in French. Giving too many of those is bound to confuse the student. Giving too few will raise questions of "why isn't his also correct?". You can't win.