$1.(20$ Points, $5$pts $/$each$)$ True or false, write your answer $($T or F$)$ in front of each statement.

$1)$ A regular grammar is a special case of context$-$free grammars.

$2)$ Nondeterministic finite automata are more powerful than deterministic finite automata.

$3)$ Turing machines are more powerful than pushdown automata.

$4)$ Two$-$tape Turing machines are more powerful than ordinary one$-$tape Turing machines.