It was not until she got home ____ Jennifer realized she had lost her keys. [ ]

It is said that the early European playing-cards ______ for entertainment and education

下列句子中，加线词语使用恰当的一项是 （ ）

Susan, whatare the advantages of MP5 players—Mom, they aresmaller and lighter ______ they can be carried very easily.

My mother still keeps in with her old friends now.