Explanation:

- Option 1, as if he had not see: This option contains a grammatical error. The correct phrase should be "as if he had not seen." The past participle "seen" should be used instead of the base form "see."

- Option 2, staring at the elephant: This part is grammatically correct. It describes the action of continuing to look at something.

- Option 3, one before: This part is also correct. It refers to something being seen previously.

- Option 4, He continued: This is correct as it starts the sentence in a coherent manner.