地面观察者看雨滴竖直下落时，坐在匀速前进的车厢中的乘客看雨滴是（ ）
A：向前运动
B：向后运动
C：倾斜落向前下方
D：倾斜落向后下方
STUDY ENGLISH IN AMERICA
Country
Tina comes from ____.
Weekend Activity
Tina visits____ on Sundays.
Location
Tina's host family is in a ____ area.
TV Program
Tina always watches ____ in the evening.
Study Time
Stay for ____ and study English as Tina does!
Although I have made a lot of new friends, Nancy remains my best friend.
下列关于血管的叙述正确的是（ ）
