叶轮键槽裂纹深度在（）以内时可经将裂纹打磨掉后继续作用，但挖修时需要大过度圆角半径。

男性，67岁，头痛、头晕、心悸6年余，加重伴视力模糊1周就诊。查体：血压180/100mmHg，神志清，双肺呼吸音清，未闻及啰音，心率90次／分，律不齐，可闻及早搏，未闻及杂音。眼底Ⅲ级。

该病需与如下疾病相鉴别（）

A.原发性醛固酮增多症

B.嗜铬细胞瘤

C.皮质醇增多症

D.肾血管性高血压

E.肾实质性高血压

F.主动脉缩窄

G.青光眼

此题要求改正所给短文中的错误。对标有题号的每一行做出判断:如无错误,在该行右边横线上画一个勾(√);如有错误（每行只有一个错误）,则按下列情况改正：

此行多一个词:把多余的词用斜线（\）划掉,在该行右边横线上写出该词,并也用斜线划掉。

此行缺一个词:在缺词处加一个漏字符号（∧）,在该行右边横线上写出该加的词。

此行错一个词:在错的词下划一横线,在该行右边横线上写出改正后的词。

注意:原行没有错的不要改。

On May Day, Li Yue and Zhang Hua, student from Class Three,           小题1: ____

Grade Two, went to Sunshine Nursing Home and do some voluntary           小题2:___

work. On their arrival, Li Yue and Zhang Hua were warm welcomed,                小题3:_____

and respectfully, they presented the elderly with flowers and fruits.            小题4:________

Then, they started working once, cleaning the windows and the floor.                小题5:________

Everything done, they sat in the yard chatted with the elderly people.        小题6:________

When there was time for them to leave, the elderly people thanked             小题7:______

them their kindness. They said it was so beautiful a day that they             小题8:_____

would remember forever. Li Yue and Zhang Hua were very happy.             小题9:____

How they did has brought joy to others and enriched their own lives.           小题10:_____

如图表示用燕麦胚芽鞘做的实验，A、B不给照光，C、D照右侧光，能够向左弯曲生长的[ ]

A．

B．

C．

D．

将长度L₁为200m截面A₁为95mm²的铝芯电缆换算为截面A₂为70mm²铜芯电缆，其等值长度为多少？（已知铝的电阻率ρ₁=0.031Ω.mm²/m，铜的电阻率）

根据分组数据计算均值时，利用各组数据的组中值做为代表值，使用这一代表值的假定条件是（）。

A.各组的权数必须相等

B.各组的组中值必须相等

C.各组数据在各组中均匀分布

D.各组的组中值都能取整数值