主要生油、气岩石（）岩。A、火成 B、沉积 C、变质 D、岩浆 发布时间：2019-01-15 16:13 │ 来源：www.tikuol.com 题型：单项选择题 问题： 主要生油、气岩石（）岩。A、火成B、沉积C、变质D、岩浆
题型：单项选择题 选词填空。从下面方框中选择适当的选项填入短文中，使短文通顺、完整。选项中有两个选项是多余选项。A. back B. passed C. end D. agreed E. happily F. but G. wrote H. away I. to J. beginning K. strange L. angrily Once a man went to the sea for his summer holidays. He asked his housekeeper to post him all letters that he would receive when he was 1 . The housekeeper 2 to do that. The man had a good rest. A month 3 but he received no letters. He thought it 4 and rang up his housekeeper: "Why didn't you post my letters?" "Because you didn't leave me the key 5 the letter box," was the reply. The man apologized and promised to send 6 the key. A few days later he put the key into an envelope, 7 down his address on it and posted the letter. Another month passed 8 still he didn't receive the letters. . When at the 9 of the month he returned home, he spoke 10 with his housekeeper. "But what could I do?" asked the poor housekeeper. "The key which you posted was in the lockedletter box, too. " 查看答案
题型：单项选择题 已知某化学式为MSO4。的物质的相对分子质量为160。 (1)M元素的相对原子质量是____； (2)根据原子的相对原子质量确定M元素的名称是______； (3)MSO4中M元素的质量分数是__________（用百分数表示）。 查看答案