Some questions must be answered with a cross in a box . If you change your mind about an
answer, put a line through the box and then mark your new answer with a cross .
1 The heart rate at rest changes during exercise.
The diagram below shows different stages in the passage of electrical activity
through the heart during one heartbeat.
The arrows and numbers represent the different stages.
Place a cross in the box next to the correct number or word to complete each
of the following statements.
The number in the diagram that represents the bundle of His is
A 1
B 3
C 4
D 5