solve this problems on turing machine

For each of the following languages A, determine whether A is semidecid- able, and whether A is semidecidable. Justify your answers. 1. A1 = {hMi| M is a TM and M, starting with a blank tape, eventually writes a nonblank symbol} 2. Let A2 be the set of all Turing Machine descriptions hMi such that M, during the computation starting with a blank tape, never attempts to move its head left when its head is on the left-most tape square. (Here we use the textbook’s convention that the tape is one-way infinite to the right.) 3. Let A3 be the set of all hMi such that M is a Turing machine and L(M) contains infinitely many even length palindromes. (Recall that these are strings of the form wwR, where wR is w written backwards). Here we assume that Σ = {0,1}. 4. A4 is the set of all hG1,G2i such that G1 and G2 are context-free grammars, and L(G1) = L(G2).