there are mang boys playing the footballsi think it must be teenagers having fun这当中的playing having 前为什么不用加be动词,这涉及到什么语法知识?

mang...are there能不能加There is which boys are there? 英语翻译how mang animal are they?how mang animal are there?是哪一个? how mang seasons are there in ayear?what are they? how mang seasons are there in ayear?what are they? Boys are over there sudu there are mang flower s in the garden.mang flowers 划线提问 THERE ARE MANG KINDS OF __________(FISH) IN THE LAKE There are mang different（ ）of fish in the lake、 There are mang birds ____ the tree.填介词 帮个忙.. 中文翻译：How mang classrooms are there in our school? how mang shop assistants are there in the shop How mang boks are there in the bag = There are mang m____ doctor in this hospital. how mang students are there in your classyisi How mang people are there in your family?的意思 how mang people are there in canada?同义句转换 How mang red things are there?的汉语