
ABO血型系统是1900年奥地利兰茨泰纳发现和确定的人类第一个血型系统。他发现,一个人的红细胞与别人的血浆交叉混合后,这些红细胞会黏连在一起发生凝集,而与另一些人血浆混合,则不发生凝集。经过进一步研究,他将人的血液分成A、B、AB、O四型。下列几种输血情况,会出现危险的是()
A.O型血少量输给B型血的人
B.A型血输给A型血的人
C.AB型血少量输给A型血的人
D.B型血输给AB型血的人


A.O型血少量输给B型血的人
B.A型血输给A型血的人
C.AB型血少量输给A型血的人
D.B型血输给AB型血的人
Read the following passage and decide whether they are true (T) or false (F).
Tourism is a modern business, or industry. In the days before inexpensive means of transportation, only the wealthy could travel for pleasure. Today, inexpensive and rapid means of travel make it possible for working people to become tourists. Leisure in the form of long weekends and paid vacations, or holidays, also makes it possible for working people to take trips.
Tourism is the name given to the business of serving tourist. Tourism is a very big business. It employs many people in many different types of jobs. Airlines are part of the tourism business. It is so important that there is a special government department for tourism. The department uses the information on the immigration cards to plan facilities for tourists. The department also advertises in many countries and helps the government and sectors (parts or sections) of the tourism industry make things easy and pleasant for the tourist.
Only the wealthy could travel for pleasure.