【正文】 n sb. in (doing) ，意為和某人一起做某事 join in 口語(yǔ)用語(yǔ)指參加（小規(guī)模的活動(dòng)，如球賽、游戲等） take part in 指參加（會(huì)議或群眾性活動(dòng)等）；強(qiáng)調(diào)所起的積極作用 Exercises: Complete the sentences: 1. He will attend an important meeting tomorrow. 2. Many college students take part in social practice during the summer holiday. 3. Come along, and join in the basketball game. 4. When did you join the army? ` 2. First, Linda and Leo learnt about the Rocket Club. learnt 為 learn 的過(guò)去式，另外 learn 的過(guò)去式可為 learned learn about 意為“學(xué)習(xí)（知識(shí)），了解 ” learn of “獲悉，聽(tīng)說(shuō)” . (1) He read a lot to learn about Chinese history. (2) I learnt of the news from TV. 2. First, Linda and Leo learnt about the Rocket Club. learnt 為 learn 的過(guò)去式，另外 learn 的過(guò)去式可為 learned learn about 意為“學(xué)習(xí)（知識(shí)），了解 ” learn of “獲悉，聽(tīng)說(shuō)” . (1) He read a lot to learn about Chinese history. (2) I learnt of the news from TV. 3. The rocket disappeared