Great changes __________ in my hometown in the last five years.

把下列几个句子组成上下衔接，语意连贯的一段话，最恰当的一组是（ ）①立秋至处暑，秋阳肆虐，温度较高，加之时有阴雨绵绵，湿气较重，天气以湿热并重为特点。②秋季的气候是处于“阳消阴长”的过渡阶段。③故有“秋老虎”之说。④“白露”过后，雨水渐少，天气干燥，昼热夜凉，气候寒热多变，稍有不慎，容易伤风感冒，许多旧病也易复发⑤被称为“多事之秋”。⑥因此，秋季养生在对精神情志、饮食起居、运动导引等方面进行调摄时，应注重一个“和”字。⑦由于人体的生理活动与自然环境变化相适应，体内阴阳双方也随之发生改变

I can’t quite remember ______you started doing the work[ ]

_____ he was very tired, he continued working in his office.

The first underground library in Beijing last year.— I’ve heard that the e-books on the train by the National Library.