在下面一段文字横线处依次填入词语，最恰当的一项是 严歌苓是位了不起的女作家，她把自己的军旅生活经历通过文字的 ，勾勒出一幅幅具有时代 的风景画，如以《芳华》为代表的部队 的作品都彰显了那个时代的活力。

Nowadays, ___motorcycle has become ___important means of transport in many cities.

I called you yesterday evening, but you were not in.—–Sorry, I _____ in the shop with my mother.

Why didn’t you keep your words，Billy—Sorry, dear. But I really forgot where I was ________to meet you.

Almost every teenager will experience a period in their life _____ they aren’t content with their parents.