there are no trees还是no tree

there are no trees还是no tree there is还是are no trees there are no trees 和there are not trees.语法都对吗?why 是 There are no things .还是 There is no things . there are no friends还是there is no friends there are no animals还是there is no animals? Look,there are no dry ____on the tree 是There is no book还是There is no books?或There are no books There are no trees In the garden 同义句 There are ___ ___trees there are no There are no accidents There are no accidents.