下列各句中，没有语病的一句是（ ）

_is often the case with elder people, my grandmatalked about my new hairstyle for at least 30 minutes.

It is fashionable to drive a car, but to drive a car is not nearly as difficult as it is imagined on condition that you ______ the specialized rules.

______, the concert began.

How could you ________ my sister so easily in the crowd? — Because she stood out in her red dress.[ ]