【单选题】The new trade agreement should _____ more rapid economic growth.
【简答题】New archaeological discovers suggest that trade between Europe and Asiaalong the Silk Road probably began in someform. many countries earlier than once thought. The findings, coupled with a widening r...
【单选题】下表列出部分化学键的键能: 化学键 Si - O Si - Cl H - H H - Cl Si - Si Si - C Cl - Cl 键能 /kJ•mol - 1 460 360 436 431 176 347 243 据此判断下列说法正确的是( )
B.
Cl 2 (g)→2Cl(g):△H=﹣243 kJ•mol -1
C.
H 2 (g)+Cl 2 (g)=2HCl(g):△H=﹣183 kJ•mol -1
D.
根据表中数据能计算出SiCl 4 (g)+2H 2 (g)=Si(s)+4HCl(1)的△H
【单选题】在图所示电路中, I 1 和 I 2 的关系是 ( ) 。
【单选题】下表列出部分化学键的键能: 化学键 Si-O Si-Cl H-H H-Cl Si-Si Si-C Cl-Cl 键能/kJ·mol - 1 460 360 436 431 176 347 243 据此判断下列说法正确的是( )
B.
Cl 2 (g)―→2Cl(g) ΔH=-243 kJ·mol - 1
C.
H 2 (g)+Cl 2 (g)===2HCl(g) ΔH=-183 kJ·mol - 1
D.
根据表中数据能计算出SiCl 4 (g)+2H 2 (g)===Si(s)+4HCl(l)的ΔH
【简答题】Chinese trade delegations have been sent to African countries, who will negotiate trade agreement.
【简答题】选择题 1 、( 2019 年浙江省高职考)下列关于抽样调研的说法,不正确的是 _____________ A. 抽样调研具有较强的准确性 B. 抽样调研时间短,时效性不强 C. 抽样调研实际上是一种专门组织的非全面调研 D. 抽样调研样本数目不足时,将会影响调研结果的准确性 2 、( 2019 年温州一模考)关于抽样调研,以下说法不正确的是 _____________ A. 抽样调研实际是一种专...
【简答题】E “You will remember this night forever,” he told me. My friend was taking me dumpster(垃圾桶)diving for the first time. We both needed costumes for a party so he decided to show me around a few of the c...
【判断题】脂肪酸的从头合成需要柠檬酸裂解提供乙酰辅酶A。