【单选题】p.p1 {margin: 0.0px 0.0px 0.0px 0.0px; text-align: justify; font: 14.0px 'PingFang SC'; color: #000000; -webkit-text-stroke: #000000}span.s1 {font-kerning: none}span.s2 {font: 14.0px 'Times New Roman'...
A.
p.p1 {margin: 0.0px 0.0px 0.0px 0.0px; text-align: justify; font: 14.0px 'Times New Roman'; color: #000000; -webkit-text-stroke: #000000}span.s1 {font-kerning: none} CaO
B.
p.p1 {margin: 0.0px 0.0px 0.0px 0.0px; text-align: justify; font: 14.0px 'Times New Roman'; color: #000000; -webkit-text-stroke: #000000}span.s1 {font-kerning: none} BaO
C.
p.p1 {margin: 0.0px 0.0px 0.0px 0.0px; text-align: justify; font: 14.0px 'Times New Roman'; color: #000000; -webkit-text-stroke: #000000}span.s1 {font-kerning: none} MgO
D.
p.p1 {margin: 0.0px 0.0px 0.0px 0.0px; text-align: justify; font: 14.0px 'Times New Roman'; color: #000000; -webkit-text-stroke: #000000}span.s1 {font-kerning: none} BeO
【单选题】The technicians are quite confident of their success, because the results of the first experiments are very _____.
【简答题】在原子序数为 1~20 号的元素中,用适当的化学符号填写下列空白(稀有气体除外).半径最小的元素是______;半径最大的元素是______;氧化性最强的单质是______;还原性最强的单质是______;最高价氧化物对应水化物中碱性最强的化合物是______;最高价氧化物对应水化物中酸性最强的化合物是______;最高价氧化物对应水化物中呈两性的化合物是______;最稳定的气态氢化物是____...
【单选题】下列物质的用途与性质对应关系错误的是( )
C.
铁粉可做食品保鲜剂——铁粉可以和空气中的氧气和水反应
【判断题】按GB7588—2003《电梯制造与安装安全规范》规定,曳引钢丝绳的安全系数是指125%额定载荷的轿厢停靠在最低层站时,一根钢丝绳的最小破断负荷(N)与这根钢丝绳所受的最大力(N)之间的比值。
【单选题】听力原文:(A) The technicians are testing their telescopes. (B) The scientists are working in the laboratory. (C) The physicians are performing an operation. (D) The soldiers are cleaning their uniforms.