It was along the Mississippi Rever ____Mark Twain spent much of his childhood.
_____it is to jump into a river to swim on such a hot day.
________ the final exam________ up soon, we should get down to our studies.
In recent years, with the help of our teacher, I have made_____ rapid progress in ____math.
Several weeks had gone by _______ we realized the painting was missing.
_______ we realized the painting was missing.
Although _______ of danger, tourists can't help taking photos near the cliff.
_______