减免税是税收优惠，下列有关减免税的表述正确的是( )。A．减免税的权限属于全国人大

尼克松1971年在堪萨斯城假日旅馆的讲话中说：“……现在，美国不再是从经济角度来说的世界头号强国，超群的世界强国，也不再仅仅有两个超级大国，当我们从经济角度和经济潜力来考虑问题时，今天世界上有五大力量，它们是美国、西欧、苏联、中国，当然还有日本。”对尼克松的上述讲话理解正确的是（  ）

A．世界出现了多极化趋势

B．资本主义世界形成了鼎足之势

C．美国丧失了霸主地位

D．世界形成了“一超多强”局面

Dear classmates:

We have some interesting and fun things for you these three months. On April 1st, we have a school trip with all the teachers. We can play all the day and we don't have classes the next day.

 小题1:   May is a great month.     小题2:   You can have a good time with your family.

 小题3:   He teaches our school team to play in the morning. On 23rd and 25th, we have two basketball games.    小题4:   all the students can watch it in the afternoon. School Day is on June 18th.    小题5:   And on June 28 after the Terminal Exams (期末考试), we have a book sale in the school library,

Have a good time!

A．Does it sound great?

B．Do all the students like?

C．Art festival is on June 2nd,

D．Your parents can come to our school.E. All the students can come to their schools.

F. From May 1st to May 7th, we don't need to come to school.

G. On May 20th, a famous sports star YaoMing comes to our school.

诗歌是鲜活的历史，向我们讲述了历史的沧桑和社会的变迁。诗句“四万万人同一哭，去年今日割台湾”与下列哪一事件相关？(　　)

A．鸦片战争

B．第二次鸦片战争

C．甲午中日战争

D．抗日战争

在等电位作业过程中出现麻电现象的原因是什么？

麝香与中枢兴奋药对中枢神经系统的影响，其主要区别在于麝香（）