初中英语数词的用法填空题

It's never too old to learn． Karl Max began to learn Russian in his　　 （ fifty）．

I usually have fast food　　（one） a week．

I have already asked him　　（two）but he hasn't given me any reply．

Karl Marx began to learn another foreign language in his　　（fifty）．

Please pass me the　　dictionary from the left in the bookcase．（six）

There are three 　　students in their school．（thousand）