Complete the summary by choosing one sentence (A,...

Câu hỏi: Complete the summary by choosing one sentence (A, B, C or D) that is among the most important information to fill in the blank.SUMMARY: This passage discusses types of star. One way to categorize stars is by temperature, which can be determined from the star’s color and Wien’s Law. _______________ . Binary stars revolve around a common center and call for telescopes with high resolving power.

A Variable stars may differ in the amount of energy they radiate or in their luminosity.

B Variable stars change in brightness and luminosity, and require a telescope with a large lens.

C Proxima Centauri, the closest star to Earth, is a binary star and requires a large telescope for observation.

D  Many different types of stars exist, but the most important categories are variable and binary stars.