Dear philip,
i just got back from a trip to the grand canyon last week. this was my first choice for a vacation. i had heard it was one of the seven natural wonders of the world. i went with my cousin, whom we all like. you will meet her someday. i heard you went to alaska. whose idea was that? it must have been freezing!
we took pack mules all the way to the bottom of the canyon. everybody was very tired near the end of the trip. all in all, it was a great trip, but i need to get back to my science paper. it’s due tomorrow.
which sentence from the passage contains a relative pronoun?

a lot

explanation:

21 balloons is the story of professor william sherman's travels.

in 1883, he set off from san francisco for a balloon ride over the pacific and was found a month later floating with 21 balloons in the atlantic ocean. this seemed an astounding feat and everyone wanted to know what had happened.    

professor sherman was loyal, however, and said he would tell his tale first to the western american explorers club in san francisco, of which he was a member. this built up suspense for several chapters before he began to tell of the wonders of his adventures and the amazing island of krakatoa, an island which had just been blown up by a volcano.  

the residents of krakatoa are all millionaires who live under a "gourmet government" of their own devising. we get to see all the incredible adventures that creative people with unlimited resources would create according to the author.

you can buy 12 peppers or less. $1.50*12 = $18