具有CD4分子表面标志的是( )

A．TC
B．TS
C．TH
D．NK细胞
E．嗜酸性粒细胞

The little child usually felt frightened at night, so not until ___________.

A．did he fall asleep his mother left the room

B．he fell asleep had his mother left the room

C．did he fall asleep did his mother leave the room

D．he fell asleep did his mother leave the room