Which of the following are the first organisms to have a one-way digestive system? A. roundworms
B. flatworms
C. jellyfish
D. sponges

If a robot fixed another robot is it a engineer or doctor?

Out of the seven main animal groups (fish, mammals, birds, insects, reptiles, amphibians, and arachnids), how many contain members with internal backbones? a. 5 b. 3 c. 7 d. 1

Nasa scientists must work together to make sure that everything is correct and accounted for when launching a shuttle. besides a physicist, what other type of scientist would be in making sure that the shuttle has the appropriate type and amount of fuel to reach its destination?