please help me 2-9 it is very simple 2 minutes per problem at most

1. (1 pt) Write the 2 lines of code to print "Hello world! " (one is an include statement). #include ustawis printf("Hello world ) 2. (1 pt) What are the three functions needed to print to the console, a file, and a string? { printf, scenti 3. (1 pt) Fill in the struct below, which will define a person with name and age; struct person { public const chernome* ir const gott oge ; 4 (1 pt) Write the typedef you need so you can write in C person p; (instead of struct person p:) typedef Person struct person {...} ! $/(1 pt) To use command-line arguments, fill in the signature for main int mainc argc a rgv[i] {- } (1 pt) Write the code to test if the number of command line arguments is not 1, and write an error message: "Usage: /hello names" and exit in that case. fprintf (stderr, "Wasci thell nanes"); exta); /(1 pt) Given the following code: int age = 21; const char* name = "Ethan": Using age and name, write the single line of code to say, "Hello, Ethan, you are 21 years old ": printf ("Hello Ether, you are 21 you old h more) i 8X (1 pt) Given this code char buf (BUFLEN] : What statement will clear buf? sconf (9. (2 pts) Write the code to count the number of characters in its input, and print it out. non ax adah Nou ds, ax trou do, offset buffer while (EoF) return uiz: basic C i/o 29 Jan 20 CPSC-223C