绿色贸易壁垒是一种关税壁垒。
参考答案：错
完全燃烧500g汽油能放出______J的热量（已知汽油的热值是4.5×107J/Kg）
According to the regulations for life boat falls，which action must be taken at 30-month intervals?（）
A.End-for-ended
B.Renewed
C.Inspected
D.Weight tested
