等温、等压、等质量的气体:H2、D2、T2,下列叙述中正确的是 ( )①摩尔质量之比为l︰2︰3 ②质子数之比为6︰3︰2③中子数之比为0︰3︰4 ④体积之比为6︰3︰2
My friend showed me round the town, ______ was very kind of him.
They use computers to keep the traffic _______ smoothly.
If you leave the club, you will not be_____back in .
What I need is_____ book that contains ______ABC of oil painting.
Jenny nearly missed the flight______ doing too much shopping.