有一分子式为C8H14N2O5的二肽，经水解后得到α丙氨酸和另一种氨基酸X，X的分子式可能是( )A.C3H7NO3
-------There were already five people in the car but they managed to take me as well . ------- It ______ a comfortable journey . A. can’t be B. shouldn’t be C. mustn’t have been D. couldn’t ha
为了开展研究性学习，同学们搜集了以下图片资料。这些资料反映的学习主题是A．大跃进B．三大改造C．文化大革命 D．改革开放
Only _____ as an interpreter _____ how important it was to practise speaking English. A. when did I work…I realized B. when did I work…did I realize C. when I work…did I realize D. when I worked
（本题10分）设数列是等差数列，数列是各项都为正数的等比数列，且，，． （1）求、的通项公式；（2）求数列的前10项和．
下列物质中，属于氧化物的是（ ） A．氧气B．水C．空气D．盐酸
检验Na2SO4 溶液中含有Cl的方法是 A．先加BaCl2溶液，再加AgNO3溶液B．先加AgNO3溶液，再加稀HNO3C．先加足量的Ba(NO3)2溶液，再加AgNO3溶液D．先加足量Ba(OH)
23．Looks are not________. It's what's inside you that really matters． A．anything B．something C．everything D．Nothing
