--- Hello, Jack! How are you doing?

--- _________.

A．Reading a magazine

B．That’s all right

C．OK

D．It’s nice

云南丽江古城冬无严寒、夏无酷暑的主要原因是                                                                [     ]

A 、濒临海洋                        

B 、人口稀少

C 、海拔较高，北面有更高山脉分布    

D 、地势低平