Translation:Of course, there were dangerous movements to avoid.
Certainly and Surely are exact synonyms. I'm not sure, but I believe DL requires the moderators to tabulate every possible response (with just a little automation in the contractions), or it won't be accepted. So the only explanation is that they just haven't gotten around to it yet (or it hasn't been reported).
Just letting you know that 'surely' is not used in this context in UK English. It doesn't mean 'certainly'. Ironically enough, it tends to be used when someone is unsure of a situation: e.g. "Surely she knew you didn't take sugar?" - i.e. the speaker is pretending that this is the case for the sake of gossip. Otherwise it turns up in stock phrases such as 'slowly but surely'. Thanks
I think the given statement is stronger than that. If it wanted to say "some dangerous movements" it would probably have been worded "quelques mouvements dangereux". But, as the plural of un mouvement is des mouvements, hence the absence of the word "some". I hope that makes sense.
My attempt to translate this was "Sure, there have been dangerous movements to avoid". It marked both "Sure" and "there have been" wrong.
Here's what I think. If "avait" is the imparfait, "were," that means that the action has continued to the current time. My translation would have been correct if it were "il y a eu des mouvements...". That would mean, "there have been dangerous movements but are no longer." That's because passé composé indicates the action is completed. Is that correct?
As far as I can tell, the two accepted answers for "Bien sûr" here are "Surely" and "Of course," and not "Sure" or "Fine."
"Of course" would be someone confirming that yes, there were dangerous movements. "Of course" means the same as those two rejected options to me.
Meanwhile, "Surely" implies this is one person insisting that another person confirm that there were indeed dangerous movements. It is nearly a question when "Surely" is used.