搜题请搜索小程序“爱下问搜题”
问题 单项选择题 A1/A2型题

人体内具分化能力的最早的造血细胞是（）

A.T淋巴系祖细胞

B.红系祖细胞

C.粒系祖细胞

D.造血干细胞

E.巨核系祖细胞

答案

参考答案：D

解析：造血干细胞是一类具有高度自我更新能力，并有进一步分化能力的最早的造血细胞。

单项选择题

掘进工作面的局部通风机应采用‘三专’，下列（）不包括在内。

A、专用变压器

B、专用开关

C、专用线路

D、专用风机
查看答案
填空题

A Great Friendship


Thomas Jefferson and James Madison met in 1776. Could it have been any other year They worked together starting then to further American Revolution and later to shape the new scheme of government. From the work sprang a friendship perhaps incomparable in intimacy and the trustfulness of collaboration and induration. It lasted 50 years. It included pleasure and utility but (1) and above them, there were shared purpose, a common end (2) an enduring goodness on both sides. Four and a half months (3) he died, when he was ailing, debt-ridden, and worried about his impoverished (4) , Jefferson wrote to his longtime friend. His words and Madison’s reply remind us (5) friends are friends until death. They also remind us that (6) a friendship has a bearing on things larger than the (7) itself, for has there ever been a friendship of (8) public consequence than this one
"The friendship which has subsisted (9) us now half a century, the harmony of our political (10) and pursuits have been sources of constant happiness to me through (11) long period. It’s also been a great solace to me to believe that you’re (12) in vindicating to posterity the course that we’ve pursued for preserving to them, (13) all their purity, their blessings of self-government, (14) we had assisted in acquiring for them. If ever the earth has beheld a (15) of administration conducted with a single and steadfast eye to the general (16) and happiness of those committed to it, one (17) , protected by truth, can never known reproach, it is that to which our (18) have been devoted. To myself you have been a pillar of (19) throughout life. Take care of me when dead and be assured that I (20) leave with you my last affections." A week later Madison replied—"You cannot look back to the long period of our private friendship and political harmony with more affecting recollections than I do. If they are a source of pleasure to you, what aren’t they not to be to me We cannot be deprived of the happy consciousness of the pure devotion to the public good with which we discharge the trust committed to us and I indulge a confidence that sufficient evidence will find in its way to another generation to ensure, after we are gone, whatever of justice may be withheld whilst we are here.\
查看答案