弧长公式l=nπR180中,当圆心角n一定时,变量是l,R.
故答案为:l,R.
—You haven't said a word about my new coat, Brenda. Do you like it?
—I'm sorry. I anything about it. I certainly think it's pretty on you.[ ]
A. wasn't saying
B. don't say
C. won't say
D. didn't say
油品罐的安全附件主要有( )、阻火器、放水阀、排污阀。
A.安全阀B.呼吸阀C.泄压阀D.报警器