What organelle is labeled E?

What protects the lining of the stomach from acidic gastric juices?

Why do you think the puppy litter was all dark-haired?

Ricardo notices that when he plays soccer in the rain, his ball does not seem to go as far after a kick. what is the best scientific question that ricardo could ask about this observation? is soccer better played in the rain or sun? how does rain affect the distance a soccer ball can travel? how does rain affect the speed of a soccer ball? is soccer affected by the rain?