Acquer applied on fingernails and toenails to decorate and/or protect the nail plate

Idon understand these and need some ! ?

Pthreads programming: create and terminate a thread write a c++ program that creates a thread. the main will display a message “hello world from the main”. the main will create a thread that will display a message “hello world from the thread” and then terminates with a call to pthread_exit()

State 7 common key's for every keyboard