[多项选择]六米顶装焦炉炭化室机焦侧宽度为（）mm。
A. 机侧420
B. 机侧440
C. 焦侧460
D. 焦侧480

{{B}}Columbia University{{/B}}
Columbia University is one of the toughest universities to get into in the U.S. Coursework at Columbia University is challenging, most notably in a number of required courses within the core curriculum. The core accounts for 90 percent of the work here. Without it, Columbia would be a breeze. The University is teeming with tremendous intellectual activity in just about any field imaginable, and accomplished scholars with mind-boggling brainpower can be found in nearly every department if they are available~ Columbia is a haven for the self-motivated. No one is going to hold your hand. Though students say their school is run pretty efficiently, many students see considerable room for improvement. The administration sometimes restricts you instead of helping you, as one student put it. The library and research resources are poorly lit but truly dazzling. Almost