下列实验所采取的的措施，不涉及“降低化学反应活化能”原理的是（  ）

⑴原码就是二进制定点表示法，即最高位为符号位，“0”表示正，“1”表示负，其余位表示数值的大小；

⑵反码表示法规定：正数的反码与其原码相同；负数的反码是对其原码逐位取反，但符号位除外。如二进制原码10010，则反码11101(注：在10010中，左边的1为符号码，故为负)；

⑶补码表示法规定：正数的补码与其原码相同；负数的补码是在其反码的末位加1，符号位除外。

根据以上运算规则，二进制有符号数100011的补码的十进制表示是(  )

材料一：唐太宗引用古人的话说：“舟所以比人君，水所以比黎庶，水能载舟，亦能覆舟。”

材料二：唐太宗：“自古皆贵（认为……尊贵）中华，贱（轻视）夷狄，朕独爱之如一。

材料三：《唐六典》记载唐王朝曾与三百多个国家和地区交往，每年都有大批外国客人来到长安。

   Mr. and Mrs. Clark are 70 years old. They look young and they are very healthy. Why? Let me tell you. That’s because they have a healthy lifestyle.
   They exercise every day, and every morning they exercise in the park. After that they usually go to the supermarket. They walk there for about half an hour. They don’t take buses. Because they think walking is good for their health. They often take a walk after dinner.
They also have a good eating habit. They drink milk every morning. They eat fruit and vegetables every day. As for meat, they only eat it twice a week. Besides (除…之外) that, they never eat junk food. They don’t drink coffee or cola at all. You see, they look after their health very well.
   Mrs. Clark likes watching soap operas and reading books. She reads books every day. Mr. Clark likes Chinese paintings. They usually go to bed at 9:00 pm and sleep for eight hours every night.

云南昭通市鲁甸县某中学正在上课时突发地震，由于该校平时进行过疏散演练，避免了师生人身伤亡事故的发生。下列是该校同学的一些做法，值得我们学习的有（    ）

①积极参加疏散演练活动，提高应急逃生能力

②地震发生时，不惊慌

③在地震刚刚发生的第一时间有序撤离教学楼

④来不及撤离时就紧靠墙根或者尽快躲到课桌下面，同时用手或书包护住头部