What most likely caused the ice ages?

In the reading, yao chen-yuan describes traveling to deliver a message. why was he willing to risk danger to travelto tientsin? he wanted to the boxers with their cause

Water is important for the of cells. a: size, shape, and temperature b: temperature, color, and odor c: color, odor, and size d: shape, temperature, and color

Suppose a lab group reports a ppercent yield of sand of 105. is it really possible to collect more sand than was originally represented? what is the possible explanation for the extra product?