【简答题】Translate the following into Chinese Not all polymers are built up from bonding together a single kind of repeating unit. At the other extreme , protein molecules are polyamides in which n amino acid ...
【单选题】Found in the chromatin of all eukaryotic cells, histones have molecular weights between 11,000 and 21,000 and are very rich in the basic amino acids arginine and lysine which together make up about __...
【简答题】words test 一、填空题 1、 He has a special feeling for the brilliant birds,and each spring he eagerly ______ their return. Thanks to the ______ of air transport,everyone is free to go to anywhere at any tim...