Sentence: One cannot really believe that there are really little green aliens...

[Paulina]

One cannot really believe that there are really little green aliens who fly all the way to our planet just so that they can kidnap people.
Is there any word to be dropped out.Does 'just' fit the sentence?

In a sentence below I found a mistake 'because' and changed it to 'which' or 'that'. Am I right?

He was looking for the elusive Great Southern Continent, because people at that time believed covered most of the Southern Hemisphere

Thanks in advance!

[Mister Micawber]

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One cannot really believe that there are little green aliens who fly all the way to our planet just so they can kidnap people.
Is there any word to be dropped out.-- I dropped them.
Does 'just' fit the sentence? -- Yes.

In a sentence below I found a mistake 'because' and changed it to 'which' or 'that'. Am I right? -- Yes.

He was looking for the elusive Great Southern Continent, which people at that time believed covered most of the Southern Hemisphere.
_________________
Native English teacher at Mister Micawber's

[Lost_Soul]

Hi, MM

Is "to kidnap" a natural choice here?
I mean, maybe "to abduct" goes better with "aliens", doesn't it ? (I'm saying this because of the numerous times I heard that aliens abduct people, and never - kidnap them)

[Mister Micawber]

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You're probably right, Alex. Kidnap means abduct for ransom, but natives (like me) are seldom careful in their usage.
.
_________________
Native English teacher at Mister Micawber's