阅读下面短文，按照句子结构的语法性和上下文连贯的要求，在空格处填入一个适当的词或使用括号中词语的正确形式填空。
When Mark first arrived in Thailand, he saw an old man selling something cheap in the street of Chiang Mai. The old man was one of the poor people in Chiang Mai and there was no   (different) from beggars (乞丐). Most of them were some lonely old people. Their life had no support.
Mark was a kind man, so he gave some change to him   thinking. The old man told him to pick something he liked. Mark didn’t choose     (something) and left.
But the old man followed him closely. At first, Mark didn’t think a lot, just supposing he wanted to go home. But when he went out very far and saw the old man still      him, he was a bit tired, thinking the old man must feel he was kind and wanted to beg more money from him.
Mark turned back and told him not to follow him     he hadn’t much money. But the old man seemed not to understand what he     (mean), still following him. The bag on his back made him sweat (流汗) all over.
Mark happened    (meet) his Thai colleague (同事) in the street and his colleague heard this. The colleague turned to ask why the old man was following his friend.
The old man said out of breath, “My son, you gave me money, but didn’t want my things, so I have to give you something. I see you are a foreigner, likely not to familiar with here. I just want to follow you and show you the way.I can do for you is this.”
Mark    (shock). He said he didn’t know why, when he felt the old man was justhis father.