C.
Black holes are hanging out at the center of our galaxy by the thousands, according to scientists who have detected a bunch
of them in the neighborhood of a supermassive black hole already known to reside at the heart of the Milky Way. Researchers
said data from the NASA's orbiting Chandra X-ray Observatory allowed them to detect a dozen black holes surrounding
Sagittarius A, the mammoth black hole at the center of our spiral-shaped galaxy. Black holes, which ___24____ a variety of sizes,
are extraordinarily dense entities with gravity so powerful that not even light can escape. Based on these findings, the scientists
estimated that up to 10,000 black holes dwell within about 3 light years of Sagittarius A, boasting ___25____ our sun and located
26,000 light years from Earth. The newly detected black holes, all produced by the collapse of massive dying stars, are rare ones
that captured and bound themselves to a passing star, forming what is called a stellar binary. Black holes ____26___ are hard to
find, but the X-ray signatures of stellar binaries allowed their detection. "Black holes can form farther out from the center of the
galaxy. They gravitationally interact with stars, cosmic collisions ___27___, and lose energy," one expert in NASA said. " As
they lose energy, they sink to the center of the galaxy, the same way heavy sediment sinks faster than light sediment in water.
They get captured by the gravity of the supermassive black hole, catch a star, and voila, you have something we can see X-rays
from."
【題組】27. (A) so to speak (B) out of stock (C) by all means (D) by and large
108正式英師,感謝阿摩 高二下 (2019/03/24) They gravitationally interact with stars, cosmic collisions so to speak黑洞與其他星體的引力互動,可謂宇宙級的碰撞cosmic 宇宙的collision 碰撞so to s.....看完整詳解