Lesson 4, 'Let's practise' section 1 lists 'start', 'part', 'mart', 'cart' as words with the middle sound /ɑ:/.
Class 3 › English Text Book › Chapter 4: Let's Play with Sounds and Numbers › Topic: Saying the middle sounds /ɑ:/ and /ʌ/
Aligned to the NCTB national curriculum.