Variational principles play an important role in the formulation of many problems of mathematical physics.变分原理现在许多数学物理的表述中起着重要作用.Bernardine: You're quite wrong there. It's a special formulation that's just...
滴水板、水槽和塞孔一定要定期消毒。Make sure the draining board, sink and plug hole are regularly disinfected.她走到水槽边，把空玻璃杯灌上水。She went to the sink and ran water into her empty glass.切香肠用的刀放在水槽里。The knife for cutting sausage was sitting in...