💡 Detailed Explanation
'Shikirini' is an adverb that describes an action being repeated many times, often accompanied by a feeling of eagerness or concern. Choice 3, describing someone repeatedly looking at their watch while anxiously waiting, is the correct usage. For choice 1, 'hijou ni' (extremely) is appropriate. Choice 2 is a logical contradiction with 'ichido dake' (only once). For choice 4, 'gussuri' (soundly) would be more suitable.