精装书封壳的组合结构是什么?
参考答案:
精装书封壳组合结构里层为书封壳硬纸板、中径纸板或中径纸,表层为软质材料。
《淮南子?原道训》记载:“鲧(禹的父亲)筑城以卫(护)君,造郭(外城)以居人,此城郭之始也。”这表明当时 [ ]
A.宗法制逐步形成
B.分封制雏形形成
C.夏朝疆域基本固定
D.国家机器雏形产生
— I’m really glad to see you back.. ______ your trip to the valley interesting?
— No. it ______ very heavily there the whole time.
A.Was; was raining
B.Is; had rained
C.Was; was to rain
D.Is; has been raining