1. Give context-free grammars that generate the following languages. In all parts the alphabet is {0,1}. a) {w w contains at least one 0 and one 1} b) {w the length of w is odd} c) {W W *and w starts and ends with different symbols d) {w the length of w is odd and its middle symbol is a 1} e) {w w = WR, that is, w is a palindrome} f) The empty set g) The empty string