2．首先，我们外出时可以照顾老人，也可以陪老人聊天、下棋、做运动。(when引导时间状语从句；v.－ing作宾语)

Firstly，it__can__take__care__of__the__old__people__when__we__are__away and__can__also__accompany__the__old__people__in__having__a__chat，playing chess， and doing__exercise.

3．其次，它能在固定的时间做饭，这个时间可以根据每个人调整。(which引导定语从句)

Secondly，it__can__cook__meals__at__a__fixed__time__which__can__be_ adjusted according to__individual__needs.

4．总之，如果你有这样的机器人，会很有帮助的。(be＋of＋n.结构；if引导条件状语从句)

In__a__word，it__would__be__of__great__help__to__you__if__you__own__such a__robot.

[连句成文]

Here is a new type of robot-the household robot，which can help us in many ways.

Firstly，it can take care of the old people when we are away and can also accompany the old people in having a chat，playing chess，and doing exercise.Secondly，it can cook meals at a fixed time which can be adjusted according to individual needs.Thirdly，it can deal with emergencies.For example，if an old man falls ill all of a sudden，the robot will call doctors for help.

In a word，it would be of great help to you if you own such a robot.