The correct expression to complete the dialogue is "Estaba nevando" as it indicates snow in the past when the question was asked. Other options either describe current weather or do not correctly convey a past situation related to skiing. Thus, the past continuous tense provides the necessary context for the dialogue. ;
The best expression to complete the dialogue is 'Estaba nevando,' which means 'It was snowing' in the past. This choice accurately reflects the weather conditions at the time of skiing. Other options refer to present conditions or are not specific enough to convey a relevant past situation.
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