"They are in different school"这个短语中的“school"是单数形式还是复数形式?

"They are in different school"这个短语中的“school"是单数形式还是复数形式? school是单数还是复数? school的复数形式 Most primary school是单数还是复数 They are not from the same ( ).（famliy） famliy用什么形式?单数还是复数? There are some trees in front of our school.(改为单数形式) 名词复数形式there are so many _____students in the school,but few 在不知道回答是复数还是单数时,问句应用什么形式?is还是are? every+名词单数形式还是复数形式? She ____(study) at school.三人称单数形式是studys还是studies?Help me! I’m in a new school 改为复数形式 等等，句中的school是复数形式（schools）我漏打了