<Table> <Tr> <Td> </Td> <Td> This section needs expansion . You can help by adding to it . (April 2015) </Td> </Tr> </Table> <Tr> <Td> </Td> <Td> This section needs expansion . You can help by adding to it . (April 2015) </Td> </Tr> <Table> <Tr> <Td> </Td> <Td> This scientific article needs additional citations to secondary or tertiary sources such as review articles, monographs, or textbooks . Please add such references to provide context and establish the relevance of any primary research articles cited . Unsourced material may be challenged and removed . (April 2015) </Td> </Tr> </Table> <Tr> <Td> </Td> <Td> This scientific article needs additional citations to secondary or tertiary sources such as review articles, monographs, or textbooks . Please add such references to provide context and establish the relevance of any primary research articles cited . Unsourced material may be challenged and removed . (April 2015) </Td> </Tr>

Which of the following features is not characteristic of aromatic compounds