01 / 7The Economist≈ approximate level A26:44–6:47 .
02 / 7Big Think≈ approximate level B23:06–3:11
.
03 / 7The Economist≈ approximate level B23:09–3:18
, .
04 / 7PBS NewsHour≈ approximate level B23:34–3:42
, , .
05 / 7Big Think≈ approximate level B18:38–8:45
, .
06 / 7PBS NewsHour≈ approximate level C14:12–4:26
, , , , .
07 / 7TED≈ approximate level C14:56–5:09
, , , .