Add punctuation: At this stage Wittgenstein was much more practically minded than one might suppose given his later highly theoretical work and he not only studied the theoretical design of the propeller but he actually built and tested it
A: At this stage Wittgenstein was much more practically minded than one might suppose, given his later highly theoretical work, and he not only studied the theoretical design of the propeller but he actually built and tested it.

Add punctuation: The Bolsheviks recognised the necessity of participation in the old trade unions and in the bourgeois parliament Stalin made friends with the trade union bureaucracy and bourgeois democracy
A: The Bolsheviks recognised the necessity of participation in the old trade unions and in the bourgeois parliament; Stalin made friends with the trade union bureaucracy and bourgeois democracy.

Add punctuation: 1743 The Philistine said to David Am I a dog that you come to me with sticks The Philistine cursed David by his gods
A:
17:43 The Philistine said to David, "Am I a dog, that you come to me with sticks?" The Philistine cursed David by his gods.