Answer the following question given this paragraph: The five regions of the primitive heart tube develop into recognizable structures in a fully developed heart. The truncus arteriosus will eventually divide and give rise to the ascending aorta and pulmonary trunk. The bulbus cordis develops into the right ventricle. The primitive ventricle forms the left ventricle. The primitive atrium becomes the anterior portions of both the right and left atria, and the two auricles. The sinus venosus develops into the posterior portion of the right atrium, the SA node, and the coronary sinus. As the primitive heart tube elongates, it begins to fold within the pericardium, eventually forming an S shape, which places the chambers and major vessels into an alignment similar to the adult heart. This process occurs between days 23 and 28. The remainder of the heart development pattern includes development of septa and valves, and remodeling of the actual chambers. Partitioning of the atria and ventricles by the interatrial septum, interventricular septum, and atrioventricular septum is complete by the end of the fifth week, although the fetal blood shunts remain until birth or shortly after. The atrioventricular valves form between weeks five and eight, and the semilunar valves form between weeks five and nine. Q: Although much of the heart's basic structure is complete by the end of the fifth week, what fetal structures remain until birth or shortly after? A:
OPTIONS:
- heart shunts
- renal arteries
- umbilical arteries
- blood shunts

Answer: blood shunts

Answer the following question given this paragraph: Earth's gravity also affects the acceleration of objects that start out moving horizontally, or parallel to the ground. Look at Figure below . A cannon shoots a cannon ball straight ahead, giving the ball horizontal motion. At the same time, gravity pulls the ball down toward the ground. Both forces acting together cause the ball to move in a curved path. This is called projectile motion . Q: Which factor causes a cannon ball to move horizontally and then fall on the ground? A:
OPTIONS:
- cone motion
- fluid motion
- downward motion
- projectile motion

Answer: projectile motion

Answer the following question given this paragraph: An ionic bond is the force of attraction that holds together positive and negative ions. It forms when atoms of a metallic element give up electrons to atoms of a nonmetallic element. The Figure below shows how this happens. Q: What is the force of attraction that holds together positive and negative ions? A:
OPTIONS:
- electron bond
- magnetic bond
- integral bond
- ionic bond

Answer:
ionic bond