In Vietnam's heavily polluted capital Hanoi, teenage taxi driver Phung Khac Trung rides his electric motorbike through streets jammed with two-wheelers belching toxic fumes. Trung, 19, is one of a growing number of Generation-Z workers driving an e-bike trend in the communist nation where 77 million -- largely petrol -- motorbikes rule the roads. IMAGES AND SOUNDBITES ARRANGED IN SEQUENCES