A:a与a'
B:b与d
C:b'和c
D:c'和d
列车起动时做匀加速直线运动,下列能反映其运动的v﹣t图象是( )
读拼音,写汉字。
yǎn lèi
pǎo
bèi
____
____步
____壳
A. read a book
B. have lunch
C. go to school
D. have dinner
E. good morning