Complete the text with the Past Simple, the Past Perfect Simple or the Past Perfect Continuous of the verbs in brackets.
Fresh ice (1)
(form) around the Nautilus all
morning. We were stuck, and the situation was getting worse.
It was becoming obvious that we could go no further south
1 (2)
(talk) to the other sailors but nobody
(3)
(have) any idea about how to escape.!
(decide) to go and see Captain Nemo. He
(think) about our situation for some time,
and when I (6)
(speak) to him, he
(already I decide) how to solve the
(7)
problem. He (8)
(suggest) something which !
(not think of. We will sail under the ice to
the South Pole," he said. I (10)
(think) about the
idea for a moment and (11)
(realise) that we
might have to stay underwater for several days. It would be
extremely dangerous.​

Fresh ice (1) had formed around the Nautilus all morning. We were stuck, and the situation was getting worse. It was becoming obvious that we could go no further south. I (2) had talked to the other sailors but nobody (3) had any idea about how to escape. I decided to go and see Captain Nemo. He had been thinking about our situation for some time, and when I (6) spoke to him, he had already decided how to solve the problem. He (8) suggested something which I had not thought of. We would sail under the ice to the South Pole," he said. I (10) thought about the idea for a moment and (11) realized that we might have to stay underwater for several days. It would be extremely dangerous.

Explanation:
1. The action of forming the ice occurred before the time frame being discussed (all morning).
2. The action of talking to the other sailors happened before the time frame being discussed.
3. The sailors not having any idea about how to escape is a fact in the past, and the action had been ongoing up until that point.
6. The speaking to Captain Nemo happened in the past, before the time frame being discussed.
7. Captain Nemo had already decided how to solve the problem before the conversation took place.
8. The suggestion made by Captain Nemo was in the past, before the time frame being discussed.
10. The thinking about the idea happened before the time frame being discussed.
11. The realization occurred before the time frame being discussed.