题干
—Where did you go?
— The science museum. I ______ that the TV _____ after the car.
A：learn; is invented
B：learned; was invented
C：learn; was invented
答案(点此获取答案解析）
B
试液，通直流电，一段时间后U形管内会形成三色“彩虹”的现象，它从左到右颜色的次序是：（ ）