Lieutenant is not a part of the main clause, and it is an address to a person that is inserted into the sentence. It must be therefore separated by comas on both sides: the correct answer is a.
The power (or exponent) of a number says how many times to use the number in a multiplication.
It is written as a small number to the right and above the base number.
In this example the little "2" says to use 8 two times in a multiplication:
82 = 8 × 8 = 64
But power can also mean the result of using an exponent, so in the previous example "64" is also called the power.
Another example: 24 = 2 × 2 × 2 × 2 = 16
• the power is 4: "2 to the power 4 is 16"
• or we can say the power is the result of 16: "the 4th power of 2 is 16"
The word croissant was borrowed from the English language as "crescent" and then translated to French as "croissant"
