Last year，I worked in a middle school near my mother's house，and I stayed with her for a month．During that time，I helped her do some housework and buy some food．After the first week，I noticed that the food was（21） 　　up very quickly．Then I began keeping an eye on my mom．（22） 　　，I found thatshe would put some of the food into a paper bag and go out with it at about nine every morning．And finally，I decided to（23） 　　her．I saw her taking the food to the street children（流浪儿童）．She would also（24） 　　a lot of time talking and playing with them．One day，I talked to a neighbor and found out（25） 　　my mom was well﹣known in the area．The children were very friendly with her and

even thought of her as（26） 　　own mother．Then it hit me﹣why wouldn't she want to tell me about it？ Was she worried that I would stop（27） 　　food if I found out？When my mom got home，I gave her a big hug．I told her she didn't need to keep it a secret from me．And she told me something about the

children．Some of them lived with an old lady in a small house．（28） 　　slept on the street．For years，she was helping the poor street children（29） 　　giving them food．After she told me everything，I was so（30） 　　By how selfless（无私的）she was．As her son，I was so proud．I continued to buy food for my mom after that．But I always addedone more bag for her other children．

21．A．eat	B．eaten	C．eating	D．to eat
22．A．To my surprise	B．In my opinion	C．After all	D．By the way
23．A．call	B．annoy	C．visit	D．follow
24．A．spend	B．take	C．cost	D．pay
25．A．whom	B．where	C．that	D．what
26．A．his	B．her	C．them	D．their
27．A．buying	B．to buy	C．keeping	D．to keep
28．A．Others	B．Another	C．Other	D．The other
29．A．about	B．at	C．for	D．by
30．A．moving	B．moved	C．excited	D．exciting