[单选题]下列归纳的乳牙髓腔特点不正确的是 ( )
A.髓壁薄
B.髓角高
C.根尖孔小
D.髓室大
E.根管粗

A.可使驾驶员视物模糊或辨色困难

B.可导致驾驶员多尿或多汗

C.可使驾驶员出现定向力障碍

D.可使驾驶员出现眩晕和幻觉

E.可引起驾驶员嗜睡

There are many stereotypes (定型) about the character of people in various parts of the USA. In the Northeast and Midwest, people are said to be closed and private (秘密的). In the South and West, however, they are often thought of as being more hospitable (好客). Ask someone from St. Nouis where the nearest sandwich shop is, and he or she will politely give you directions. A New Yorker might eye you at first and after deciding it is safe to talk to you, might give you a rather un- expected explanation. A person from Georgia might be very king about directing you and even suggest some different places to eat. A Texan just might take you to the place and treat you to lunch.
American stereotypes are abundant. New Englanders are often thought of as being friendly and United States are often considered very outgoing. These differences in character can be traced to different factors such as climate, living conditions and historical development.
When traveling from place to pl
A. New Youkers are usually open with strangers.
B. People from the South are usually considered good hosts.
C. The friendliest Americans travel from place to place.
D. Different parts have different customs and habits.