Some of the young men learn English ________ to the radio. [ ]

A. from listen

B. from listening

C. by listen

D. by listening

拆除竹脚手架的连墙杆和压栏子时，必须事先计划好连墙杆或压栏子的拆除顺序，不得乱拆一气，以防止脚手架的倾倒事故发生。