一道绝对值计算的数学题目已知M=10,N=-5,P=-8,求式子|m|-2|-n|+1/2|-p|的

在烟叶储存期间，影响烟叶质量变化的外在因素有:()。

A.环境温湿度

B.异味

C.虫害

D.烟叶化学成分

此题为多项选择题。请帮忙给出正确答案和分析，谢谢！

The basic American handshake______.

A．can be done with either the right hand or the left hand

B．is complicated and difficult to follow

C．is often done by people at an old age

D．can be done between old or new friends

请帮忙给出正确答案和分析，谢谢！

During the medieval times, if one man covered in armor extended an open hand to another, ______.

A．the same gesture would definitely be returned

B．he was sending a signal of friendship

C．he would receive a dagger or sword

D．he was asking for a weapon

请帮忙给出正确答案和分析，谢谢！

多个样本均数之间的两两比较需用哪种方法

A.t检验

B.t＇检验

C.方差分析

D.正态性检验

E.q检验

请帮忙给出正确答案和分析，谢谢！

抑制性突触后电位是

A、去极化局部电位

B、超极化局部电位

C、具有全或无特征

D、突触前膜递质释放减少所致

E、突触后膜对Na+通透性增加所致

请帮忙给出正确答案和分析，谢谢！