English: college entrance examination questions. Ask for an explanation.

Building our company into what it is today requires a lot of hard work and careful planning.

Explanation:

1. This sentence adopts it take sth to do sth, followed by to do sth is to build my company to _ _ _ _ it is today.

The infinitive phrase contains the fixed collocation "build sth to sth", that is, _ _ _ _ _ _ _ it is today must be the noun component sth.

So this component must be a noun clause (exactly: the object clause after the preposition to).

2. There are three kinds of leading words in object clauses: that, if/where and special interrogative words.

If the object clause does not lack any elements, it will take this as a guide. That is only for guidance, has no practical significance, and is not an integral part of the terms. I didn't know you were a teacher.

If the object clause lacks the question "whether", it is guided by if/what. I wonder if/when you are a teacher.

If the object clause lacks other components, use the corresponding special interrogative words that can replace this component to guide it. I don't know what you did yesterday.

3. Back to this question, in the object clause _ _ it's today, there is obviously a lack of a predicative of sth after is, so what is used as a guide word, that is, the correct answer is B.

In answer A, if which leads to a noun clause, which means "which one …". That sentence doesn't make sense: "Build our company into what it is now"?

I don't know which one I should choose.

In answer C, if that leads to a nominal clause, then it has no practical meaning and does not act as a clause component, but there is no predicate after is in this sentence, so it is excluded.

In answer D, where leads to a noun clause, which means "in the place of …", and that sentence doesn't make sense: "Build our company into what it is today"?