01 / 8CrashCourse≈ approximate level C16:28–6:35 , .
02 / 8PBS NewsHour≈ approximate level C16:20–6:32
, , , , , 's .
03 / 8CrashCourse≈ approximate level B23:22–3:29
, , ’ ( ).
04 / 8TED-Ed≈ approximate level B10:49–0:58
— .
05 / 8TED≈ approximate level B20:08–0:18
, .
06 / 8NBC News≈ approximate level C11:43–1:49
, , .
07 / 8CrashCourse≈ approximate level C19:10–9:23
, , , .
08 / 8CrashCourse≈ approximate level C11:32–1:46
– , , , .