01 / 8Practical Engineering≈ approximate level B26:18–6:25 - .
02 / 8Practical Engineering≈ approximate level C18:23–8:28
, .
03 / 8CrashCourse≈ approximate level C19:52–10:02
’s , , — — ’s .
04 / 8Practical Engineering≈ approximate level C18:17–8:26
, , .
05 / 8Practical Engineering≈ approximate level C15:32–5:39
, -- .
06 / 8TED≈ approximate level B15:21–5:25
, .
07 / 8Practical Engineering≈ approximate level C16:47–6:55
- - .
08 / 8Practical Engineering≈ approximate level C16:42–6:53
, -- .