Please Solve These,Artificial Intelligence.ASAP

Computer Science Theory 2. Let L,-{(D? | D is a DFA over ? = {0, 1), and D recognizes the language L(1.)) Prove that L is decidable. 3. Let L2-M) |M is a TM and M accepts at least two different strings). Prove that L2 is recognizable. 4. Recall that for a language L over alphabet ?, we define grep(L)-(x E ?. | x has a substring w E L} Prove that the class of TM-recognizable languages is closed under the grep operation