,mother will wait for him to have dinner together.

A．However late is he

B．However he is late

C．However is he late

D．However late he is

婴幼儿易患呼吸道感染的主要原因是

A．呈腹式呼吸
B．呼吸频率快
C．呼吸道黏膜缺少SIgA
D．呼吸表浅
E．鼻腔短小、狭窄，黏膜血管丰富