U.S. debt tops $40 trillion. How long can America keep borrowing?

①Wang Yi visits South Korea and Indonesia. What's topping his agenda? (00:51) ②Pentagon targets 30 U.S. universities over Chinese research ties. A new "Cold War" in science? (11:45) ③China, Australia expand currency swap agreement. Is Australia hedging against its dependence on the U.S. dollar? (24:09) ④U.S. national debt tops $40 trillion for the first time. How much longer can America sustain…