根据下列句子及所给汉语注释，写出空缺处各单词的正确形式。（每空只写一词）
I’d like to be a _________(志愿者) in the next Olympics.
The machines are checked on a ________(定期的) basis.
In my spare time , I took a course in art and ________(设计).
The two ________(德国人) and three Englishmen are all my friends.
The students are mostly ___________(青少年) between 16 and 19.
I don’t think it good to keep small children sitting _________(直) all the time in class.
In spite of his illness, he carries on working as _________(往常).
His apartment is three __________(街区) away from our school.
His pet dog died and he ________(埋葬) it under a tall tree.
There is an _________(相等的) number of boys and girls in this class.