James said, "Hurry up! The store D. closes."

Explanation: This is a general statement about the store's regular action, so the present simple tense is used.
William said that he had C. three days before become a conservationist.

Explanation: When reporting past events, the correct indirect speech form for time expressions is "before" (not "ago" or "previous").
Samuel said to his friends that D. he wanted to become a conservationist.

Explanation: The past tense is used in reported speech to match the tense in the original statement.
He said, "No matter what A. happens - I will support the new project."

Explanation: The present simple tense is used in reported speech when talking about future events in conditional sentences.
The teacher said that their school D. would equip new computers in the library.

Explanation: In indirect speech, the future tense in direct speech changes to "would" in the past tense.
He said that his computer was downloading a big file B. at that moment.

Explanation: "At that moment" is the appropriate time expression for indirect speech, referring to a past event.
Dad said to me that the sun A. was only a small star in the universe.

Explanation: Since this is a statement about a scientific fact, the past tense "was" is used in reported speech.
Jonathan said to his friend that D. he was reading a science book then.

Explanation: The past continuous tense ("was reading") is used for an ongoing action in the past.
Susan said, "I usually take the bus to town, but A. today I cycle for a change."

Explanation: "Today" refers to the current day, and it's used in direct speech to indicate the present time.