问题
单项选择题 B1型题
表示暴露组发病率是对照组发病率的比()
A.RR
B.AR
C.AR%
D.OR
E.PARP
答案
参考答案:A
表示暴露组发病率是对照组发病率的比()
A.RR
B.AR
C.AR%
D.OR
E.PARP
参考答案:A
Complete the following passage by using the words in the box. Each word can only be used once. Note that there is one word more than you need.
The first plants to exist out of the water were probably certain kinds of algae ( 藻类 )which were followed by other plants that grew close to the ground and needed water in which to 小题6: . Once the move to land has been made, however, evolution took place quickly. By the end of 100 million years, plants had developed their 小题7: , and some have got tree-like forms since height was very important in 小题8: sunlight. About 300 million years ago, much of the world was 小题9: with forests of huge trees. In most ways they were like modern trees. They had roots, leaves, wood, but mostly they had not developed seeds. |