Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE table_43214 ( "Rank" real, "Name" text, "Span metres" real, "Span feet" real, "Material" text, "Year opened" text, "Country" text )

### Question ###
Which country's material was concrete when the span metres were less than 270, span feet is more than 837, and the year opened was 1943?

### Accurate SQL ###

SELECT "Country" FROM table_43214 WHERE "Material" = 'concrete' AND "Span metres" < '270' AND "Span feet" > '837' AND "Year opened" = '1943'