            $tmp_ids = array();
            $ids = DB::table("word")->where("level_".$level,"=",1)->get(array('id'))->toArray();
            foreach ($ids as $key=>$value){
                array_push($tmp_ids,$value->id);
            }
            $rand_num = rand(0,count($tmp_ids)-1);
            $id = $tmp_ids[$rand_num];
            //记录随机单词
            DB::table("user_rand_word")->insert(array(
                "word_id"=>$id
            ));
            $word_db = DB::table("word")->find($id);
            $words["data"]["word"]=$word_db->word;
            $words['data']["description"] = $word_db->description;
            $words["count"]=count($tmp_ids);