What are the examples of speech errors listed in section 4?

The examples of speech errors are: 1) Levitana's second trip to the Volga was more successful than the first. 2) Levitana saw the beauty of the rains and created his famous 'rainy works': 'After the Rain' and 'Over Eternal Peace'. 3) Russian nature became the main leitmotif of Levitana's work. 4) Levitana's name is known in many countries. 5) Levitana suffered from cold, from the slippery clay of the Volga banks, from the impossibility of writing in the air.