1. Jane and Mike are the same in score.

Jane and Mike are the same in a score.
Jane and Mike are the same in the score.
(For example, Jane got 90 points. Mike also got 90 points.)

Which expression is correct?

2. How does the baby look?
It looks sleepy.
(Is the question or answer correct?)

3. Wow, it's a new beginning.
(What does 'it' mean?)

3-1. Yes, it's a new semester!
(Waht does 'it' mean?)

1. Jane and Mike are the same in score.

Jane and Mike are the same in a score.
Jane and Mike are the same in the score.
(For example, Jane got 90 points. Mike also got 90 points.)
Better pheasing is this: "Jane and Mike have the same score."

Which expression is correct?

2. How does the baby look?
It looks sleepy.
(Is the question or answer correct?)
It's fine, but it would be better if you said, "He looks sleepy" or "She looks sleepy."

3. Wow, it's a new beginning.
(What does 'it' mean?)

3-1. Yes, it's a new semester!
(Waht does 'it' mean?)

In both 3 and 4, "it" doesn't have an antecedent. There is simply a general reference to time -- maybe meaning today or this week.

"pheasing" ~~> should be "phrasing"!

1. The correct expression would be: "Jane and Mike have the same score." In this case, the word "score" is used as a noun, and it is not necessary to use "the" before it.

2. The question "How does the baby look?" is correct. It is asking for the appearance or condition of the baby. The answer "It looks sleepy" is also correct as it provides a description of the baby's appearance.

3. In the sentence "Wow, it's a new beginning," the word "it" is likely referring to a situation or event being described as a new beginning. Without more context, it is not possible to determine the exact referent of "it."

3-1. In the sentence "Yes, it's a new semester!" the word "it" is referring to the new semester. It is being used as a pronoun to avoid repeating the noun "semester" in the sentence.