3. (1)A calorie is the amount of heat required to raise the temperature of a kilogram (about a quart) of water one degree Celsius. (2)To determine the number of calories in a portion of food, a technician uses a device called a bomb calorimeter. (3)This device has a chamber that rests in a container of water. (4)The food is placed in this chamber, which is _____ filled with oxygen under high pressure. (5)Next, the food is set on fire.
Click on the appropriate transition to fill in the blank.
a. finally.

b. then.

c. as.

d. before.