下列哪一项是年轻恒牙的特征（）。 A.牙本质小管粗大 B.髓角高_爱下问搜题

搜题请搜索小程序“爱下问搜题”

问题单项选择题

下列哪一项是年轻恒牙的特征（）。

A.牙本质小管粗大

B.髓角高、髓腔大

C.神经丰富

D.血管丰富、修复能力强

E.以上都是

答案

参考答案：A

改错题

短文改错。
此题要求改正所给短文中的错误。对标有题号的每一行作出判断；如无错误，在该行右边横
线上划一个勾（√）；如有错误（每行只有一个错误），则按下列情况改正：
该行多一个词：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。
该行缺一个词，在缺词处加一个漏字符（∧），在该行右边横线上写出该加的词。
该行错一个词：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。

     When I first learned to write in English, she ran into
much difficulties. The main problem was that I always thought
in Chinese and tried to translate anything into English.
My teacher advised me to keep my diary. I followed her
advice and should put down 100 words or so each day.
Soon I began to enjoy talk to myself as I was
learning to express me in simple English. One day I wrote
a story and showed to my teacher. He liked it very much
and reads it to the class. All said that the story was
a good one. Their word were a great encouragement to me.

1.________
2.________
3.________
4.________
5.________
6.________
7.________
8.________
9.________
10._______

单项选择题

小儿初次感染结核，使机体产生变态反应，同时获得免疫力的时间是( )。

A．1～2周
B．4～8周
C．10～12周
D．12～14周
E．14～16周