吊顶工程中，当吊杆长度大于( )应设置反支撑。

A．300mm

B．500mm

C．1000mm

D．1500mm

Which one of the following statements regarding cartilage is FALSE

A．Its growth rate is increased by testosterone and thyroxine

B．Its growth rate is decreased by cortisone and estradiol

C．Fibrocartilage is the cartilage model in endochondral bone formation

D．The matrix of elastic cartilage is identical to that of hyaline cartilage except that it contains elastic fibers

E．Hyaline cartilage is the cartilage model associated with endochondral bone formation.