Hello, please help me understand the construction theorem in the following problem, thank you for your help in advance

a) {w| w begins with a 1 and ends with a 0}

b) {w| w contains at least three 1s}

c) {w| w contains the substring 0101 (i.e., w = x0101y for some x and y)}

F) {w| w doesnt contain the substring 110}