Which sentence uses a verb that agrees with its compound subject? a. now either blankets or a thick coat keep us warm. b. calcium and magnesium is necessary for strong bones. c. those children and the tired adult have waited many hours. d. sam and li rides their skateboards around the neighborhood

C. Those children and the tired children have waited many hours.

The details about the statues, i believe, are that they're carved from blocks of igneous stone, many of them are partially buried under the ground which to preserve and protect them from the harsh environment on easter island, and many of the facial features have washed away. also, the most well-preserved one is at the british museum in london.these are just guesses from what i can see and what i think i read correctly. i'm sorry i couldn't be more .