问题 单项选择题

正常覆为上切牙切缘盖过下切牙唇面的垂直距离()。

A.3mm

B.4mm

C.5mm

D.颈1/3

E.切1/3

答案

参考答案:E

解析:

是指上颌牙盖过下颌牙唇、颊面的垂直距离。在前牙,盖过的部分不超过前牙唇面切1/3者,称为正常覆;超过者,称为深覆胎。深覆的程度依下颌前牙切咬在上颌前牙舌面的部位而定,咬在切1/3以内为正常覆;咬在中1/3以内为I度覆;咬在颈1/3为Ⅱ度深覆;超过颈1/3为Ⅲ度深覆。正中时,若下颌牙反盖着上颌牙,称为反;若上下牙齿彼此切缘相对,或颊尖相对,称为对刃或对

阅读理解

.

Once upon a time, there was a seed and because he was only a seed, nobody cared to notice him. Thus, feeling kind of inferior, the seed gave no importance to his existence.

Then one day, a wind picked him up and threw him on an open field under the hot sun. He wanted to know why. But instead of any answer, he was provided with rain besides sunlight, sometimes small and sometimes heavy.

Time flew and years later he saw a traveler sitting by his side. "Thank God for this. I really need some rest," he heard the traveler say.

"What are you talking about?" the seed soon asked. He thought the man was making fun of him. Sure, he had seen many people sitting by his side but no one ever spoke to him like that.

"Who's this?" the man was surprised.

'It's me. The seed."

"The seed?" the man looked at the big tree. "Are you kidding me? you're no seed. You're a big tree?

"Really?"

"Yes! Why do you think people come here? To feel your shade!"

A moment passed before the traveler's words touched the chord (心弦)  in him. The seed, now a great tree, smiled for the first time in his life. Years of sufferings from the sun and the rain finally made sense to him.

"Oh! That means I'm not a small seed anymore!  I didn't die unnoticed but was born to help people with tiredness. Wow! Now that's a life worth a thousand gems (宝石)!"

60. What does the underlined word "inferior" (in Paragraph 1) probably mean?

A. Not funny.     B. Not weak.   C. Not good.  D. Not interesting.

61. The seed thought the man sitting by his side was laughing at him because _______.

A. the man didn't think the seed was important

B. the seed never thought he could be noticed

C. the man was talking about God with him

D. the man really wanted some rest near him

62. When the seed first heard that he had been a big tree, he felt _______.

A. disappointed        B. excited    C. doubtful       D. satisfied

63. The passage mainly tells us that ________.

A. every life is of some value           B. one's existence is in need of a finder

C. life goes on no matter what happens    D. failure is the mother of success

填空题