Consider the situation where the stock price 6 months from the expiration of an option is $42, the exercise price of the option is $40, the risk-free interest rate is 10% p.a. and the volatility is 20% p.a. So the value of the call option is
【简答题】In China we address a stranger with an advanced age ”Grandpa” or “Grandma”. Why do we do so since that stranger is not connected to us by blood? How does this sound to an English ear?