Scientists would be more likely to suspect that Mars once held life if there were evidence ...
I thought that if there were certain evidence, the scientists would NOT be going to believe that Mars once held life. Because, I thought that the word "suspect" means to doubt.
But the answer was the opposite. The word "suspect" means to feel, so the sentence states that if there were certain evidence, the scientists would be going to believe that Mars once held life.
How I understand this situation. In the dictionary, the word suspect has both meanings.