Elena Bogomolovaadded a comment 6 years agoThanks! I had doubts because Ngram shows that this version is unpopular https://books.google.com/ngrams/graph?content=what%27s+up%2C+how%27re+things&year_start=1990&year_end=2008&corpus=15&smoothing=3&share=&direct_url=t1%3B%2Cwhat%20%27s%20up%3B%2Cc0%3B.t1%3B%2Chow%27re%20things%3B%2Cc0