Rather than take a bus, I prefer ____ to school. [ ]

A. walking

B. walk

C. to walk

D. to walking

铬菁R分光光度法（HJ／T58—2000）测定水中铍时，其方法检出限是0.2mg/L，在方法规定条件下，测定范围是0.7～40.0mg／L。