How many meaningful English words can be made with all the letters $ERTU$ using each letter only once in each word?

Arrange the given words in alphabetical order and choose the one that comes first:
Praise,Practise,Prayer,Practical,Prank

If all the letters in the word $PRINCE$ are rearranged in alphabetical order,then how many letter$(s)$ will remain unchanged?

If the last four letters of the word $CONCENTRATION$ are written in reverse order,followed by the next two in reverse order,the next three in reverse order,and finally the first four in reverse order,which letter would be the eighth in the new arrangement,counting from the end?

If it is possible to make a meaningful word with the second,the fifth and the eighth letters of the word $CARETAKER$,which of the following will be the first letter of that word? If no such word can be made,give $X$ as the answer. If more than one such word can be made,give $M$ as the answer.

After arranging the letters of the word $FOLK$ in alphabetical order,if each letter is substituted by the letter immediately preceding to it in the English alphabet,what will be the resultant form of the word?