下列文献中,把救国救民同中国国情相结合,代表历史发展方向的是( )
答案:D
注意题f中的条件,既代表历史方向,又与中国国情相结合,符合这一条件的也只有D选项。
— Where is Bob? I cannot find him anywhere.
— He ________ have been off long. I heard him make a call just now. [ ]
A. shouldn't
B. can't
C. mustn't
D. needn't
卤族元素按F、Cl、Br、I的顺序,下列叙述正确的是[ ]
A.单质的颜色逐渐加深
B.气态氢化物的稳定性逐渐增强
C.与氢气反应越来越容易
D.单质的熔、沸点逐渐降低