问题 填空题
写出下列各词的复数。
例: book-books 
desk ____________
skirt ____________
girl ____________
pen ____________  
school ____________
bed ____________  
chair ____________ 
boy ____________  
ruler ____________                                                     
答案

desks, pens, chairs, skirts, schools, boys, girls, beds, rulers

问答题
单项选择题