直线y=4x+b是曲线y=x⁴-1的一条切线，则实数b的值为______．

As part of the respiratory assessment, the nurse observes the neonate's nares for patency and mucus. Which of the following is the reason that the nurse employs this assessment

A．Neonates are obligate nose breathers.

B．Nasal patency is required for adequate feeding.

C．Problems with nasal patency may cause flaring.

D．A deviated septum will interfere with breathing.