[00:00.00] [00:00.73]Unit 2 Mr Li was a teacher. [00:06.66]一、Listen and tick. 听一听，勾一勾。 [00:16.59]1. M: study hard [00:24.74]2. W: teach Maths [00:31.56]3. M: go to school [00:38.70]4. W: twenty years ago