Which of the following is an opinion about the ISS? Group of answer choices.

More than 20 countries have helped build and maintain it

It proves that space travel is worth the time and effort

Many scientific experiments are carried out onboard

The Columbia space shuttle disaster caused delays in its construction

Why is the huronian supergroup rock formation particularly interesting to scientists? because it looks like a cross-section of a giant, stone encyclopedia because it formed during the period when oxygen began to accumulate in the atmosphere because it contains unusually large amounts of oxygen and sulfur because it dramatically altered the planet's development when it first formed