简述消费者收入变动对预算约束线的影响。

关于破伤风的临床表现中，下列错误的是（）

A.前期症状可有疲乏无力、头晕头痛、烦躁不安、咀嚼无力、局部肌肉发紧、反射亢进等

B.典型的肌肉持续性收缩或僵硬

C.在肌紧张性收缩的基础上伴阵发性强烈痉挛，形成"角弓反张"或"侧弓反张"

D.持续高热

E.常见并发症为肺部感染、窒息、舌咬伤等

—What’s his monthly income?

—Well, he ________ earn as ________ as 4,000 dollars a month when his business runs well.

A．can; much

B．might; many

C．must; far

D．should; high

Many people believe we will suffer from more environmental disasters _____we change the way we live.   [ ]

A. but              

B. although      

C. so                    

D. unless

纱线的密度是表示纱线（）的指标。