(对画线部分提问) Mr Green will go back to Paris in three weeksndline．

_______ __________ will Mr Green go back to Paris?

It’s Sunday today. Mr. Green goes out for a picnic. On the way 1Mount Fang,  he can’t 2the way. So he 3ask an old man near him for help.
“Could you please tell me the way 4 ?”asks Mr. Green.
“Go  5 this road,  cross the Lang Park and turn right at the gate of the park. Go up the street to the end and you’ll see it 6 your left. ” says the old man.
“How long will it take me to 7there?” asks Mr. Green.
The old man says nothing(没什么). Mr. Green feels a little angry(生气的). He goes away. After a while(一会儿),  the old man calls him,  “Young man,  you will get there in about half an hour. ”
“ 8  didn’t you tell me just now（刚才）?” asks Mr. Green.
“I don’t know how fastyou can walk. 9 I have to let you go,  then I can tell you the 10 . ”says the old man.

—What time will Mr. Green be back to China?

—Sorry. I don’t know ________.

A．when did he go broad                    B．why he is going abroad

C．how soon will he be back                 D．how long he will stay abroad

—What time will Mr. Green be back to China?
—Sorry. I don’t know ________.