“I hear Johnson was badly injured in the accident.” “_______ let’s go and see him.”

A．What’s more

B．If so

C．Where possible

D．When necessary

据科学家测算，冥王星与太阳的距离大约是五十九亿八千零五十万千米，这个数写作（    ）千米，省略“亿”后面的尾数约是（    ）亿千米。