连结“肺主呼吸”和“心主血脉”的中心环节是（）。 A.经脉的相互连结 B.气血的相互

给下面加粗字选择正确解释，在序号上打"√"。

（1） 舟行碧波上，人在画中游。

①游泳　②游览　③欣赏

（2）可怜九月初三夜。

①怜悯　②爱

（3）境遇

①边界　②地方　③遭遇到的情况

某市当日空气质量状况为良，据此判断该日的空气质量指数位于（）

A.<50

B.51～100

C.101～200

D.201～300

E.301～400

可用于制备疫苗的结核分枝杆菌的变异是

A．形态

B．结构

C．毒力

D．耐药性

E．菌落

在代办股份转让业务中，提供股份转让业务的是( )。

A．提供业务设施的证券服务公司
B．证券交易所指定的公司
C．非上市公司选定的银行
D．非上市公司股份转让的主办券商

People born in autumn live longer than those born in spring and are less likely to fall chronically ill when they are older, according to an Austrian scientist, Using census (人口普查) data for more than one million people in Austrian. Denmark and Australia, scientists at the Max Plank Institute for Demographic (人口统计的) Research found the month of birth was related to life expectancy over the age of 50. Seasonal differences in what mothers ate during pregnancy, and infections occurring at different times of the year could both have an impact on the health of a new - born baby and could influence its life expectancy in old age. "A mother giving birth in spring spends the last stage of her pregnancy in winter, when she will eat fewer vitamins than in summer. " said one of the scientists. "When she stops breast - feeding and starts giving her baby normal food, it’s in the hot weeks of summer when babies are inclined to infections of the digestive system. " In Austria, adults born in autumn lived about seven months longer than those born in spring, and in Denmark adults with birthdays in autumn outlived those born in spring by about four months. In the southern hemisphere, the picture is similar. Adults born in the Australian autumn lived about four months longer than those born in the Australian spring. The study focused on people born at the beginning of the 20th century, using death certificates and census data. Although nutrition at all times of the year has improved since then, the seasonal pattern persists.

The term "life expectancy" (Line7) refers to（）。

A. the average period that a person may expect to live

B. the length of time for each person

C. the expectations of a person’s life

D. the seasonal changes in a person’s life