A—bicycle lane
B—streetlight
C—underpass
D—main intersection
E—traffic light
F—police stand
G—toll-paying road
H—petrol station
I—lane separator
J—footbridge
K—alley
L—flyover
M—zebra crossing
N—expressway
O—tollgate
P—traffic accident ( )天桥 ( )人行横道

A．the development of babies’ early forms of language
B．the difficulties of babies in learning to speak
C．babies’ strong desire to communicate
D．babies’ intention to communicate