转K2型转向架减振弹簧外圈圆钢的直径为（）。
A、Φ18mm
B、Φ20mm
C、Φ23mm
D、Φ25mm
参考答案：A
先天禀赋不足，首先影响的是（）
A．卫气
B．元气
C．清气
D．水气
E．谷气
In relation to the law of contract:
(b) Explain the ways in which an offer may be revoked as provided under the Contracts Act 1950. (5 marks)
