Please help with code and Thank you!

3) (3 points) The first two steps have helped us collect data from web resource. Then we are going to preprocess the article by removing some less important words from the text file, such as "a", "the" and so on. These words are not used for text mining. Please write a C program removeChar.c to finish this task. To simplify this problem, your C program just needs to obtain the input from standard input and remove only word Hint: you do not need to know how to read a file. Please use getchar() to obtain the input.] 4) (2 points) Write a single line shell command to run the C program above and remove all words "a" from the file news.txt 5) (3 points) Please write a C program removeWord.c to obtain the input from standard input and remove all word "the". 6) (4 points) Please write a C program countSentence.c to obtain the input from standard input and count the number of sentences. Assume a sentence should end with., .", ? or!. 7) (Bonus: 4 point) Please write a C program listFreq.c to list the frequency of each word from the standard input