NASA announced that the Spitzer infrared space telescope had found a system of seven Earth -sized planets,three of which are in its star's habitable zone, the region around a star where liquid water can survive on the surface. The star is called TRAPPIST-1 . It is a small red dwarf star 39 light - years from Earth . Initial observatons of the systems forund three planets by their transits - that is , by observing the dimming they cause when they pass in front of their star._____________. They are not too close to the star , so liquid water won't boil away, They are not too far away , so liquid water will not permanently freeze.

Answer

B

Explanation

The statement before the blank is talking about three planets and statement after the blank states the features of those three plants so this implies the statement required should be about the third plant. In option C, firstly the .have. should be replaced by .has. because of the subject pronoun .it. or the .it. should be replaced by .they. . Also , the statement is talking about one thing or one planet. Thus, it doesn.t accord with the statement followed by blank having mentioned .they.. In option D, .the masses.. Statement E is a result therefore, it should not be placed in between rather it should be placed at the end of the passage.