补体易受什么理化因素影响?
参考答案:
补体性质不稳定,易受各种理化因素的影响,如加热56℃30分钟即被灭活;另外紫外线照射、机械振荡或某些添加剂等理化因素均可破坏补体。
27.What do you think of his suggestion ______ we organize a football club?
A.which
B.whether
C.that
D.What
允许速度Vmax≤120km/h时,道岔直向两端过渡枕均不得少于50根;160km/h≥vmax>120km/h时,道岔直向两端过渡枕均不得少于()。
A.45根
B.60根
C.75根
D.80根