[单项选择]煤气站的生产、输送系统均应按规定设置放散管，且放散管至少应高出厂房顶( )。以上，并具备防雨和可靠的防倾倒措施
A. 3m
B. 4m
C. 5m
D. 6m

Ask an American schoolchild what he or she is learning in school these days and you might even get a reply, provided you ask it in Spanish, but don’t bother, here’s the answer: Americans nowadays are not learning any of the things that we learned in our day, like reading and writing. Apparently these are considered fusty old subjects, invented by white males to oppress women and minorities.
What are they learning In a Vermont college town I found the answer sitting in a toy store book rack, next to typical kids’ books like "Heather Has Two Mommies and Daddy is ’Disfunctional’". It’s a teacher’s guide called "Happy To Be Me", subtitled "Building Self-Esteem". Self-esteem, as it turns out, is a big subject in American classrooms. Many American schools see building it as important as teaching reading and writing. They call it "whole language" teaching, borrowing terminology from the granola peo
A. the whole concept of communication is being perceived differently
B. the way American children communicate among themselves is more important than anything else
C. academic skills should be encouraged and promoted in the American education system
D. the progress that American children could be monitor with more traditional methods