docs: correct a few missing changes

docs-cn/12-taos-sql/07-function.md

@@ -668,7 +668,7 @@ SELECT LEASTSQUARES(field_name, start_val, step_val) FROM tb_name [WHERE clause]
 SELECT MODE(field_name) FROM tb_name [WHERE clause];
 ```
 
-**功能说明**：返回出现频率最高的值，若存在多个频率相同的最高值，输出空。不能匹配标签、时间戳输出。
+**功能说明**：返回出现频率最高的值，若存在多个频率相同的最高值，输出空。
 
 **返回数据类型**：同应用的字段。
 

docs-en/12-taos-sql/07-function.md

@@ -281,7 +281,7 @@ SELECT CONCAT(str1|column1, str2|column2, ...) FROM { tb_name | stb_name } [WHER
 
 **Return value type**: If all input strings are VARCHAR type, the result is VARCHAR type too. If any one of input strings is NCHAR type, then the result is NCHAR.
 
-**Applicable data types**: VARCHAR, NCHAR. Can't be used on tag columns. At least 2 input strings are requird, and at most 8 input strings are allowed. 
+**Applicable data types**: VARCHAR, NCHAR.  At least 2 input strings are requird, and at most 8 input strings are allowed. 
 
 **Applicable table types**: table, STable