理学
名词解释题暗视野显微镜（dark—field microscope）
题目
参考答案和解析
相似问题和答案
第1题：
Which of the following statements is NOT true?（）
AThe open field system provided a good opportunity to experiment.
BThe open field system wasted land.
CThe open field system was wasteful of labor and time.
DThe open field system made livestock farming difficult.
A
略
第2题：
Yuri created a formula for a button. The code is supposed to set the value of an existing field called title. He used the following formula: title:= @propercase (title); after the foumula runs ,the title field is null. Why? （）
- A、the value of one field cannot be set from the value in another field
- B、the text string in the formula is set to null. Thus notes cannot validate the formula
- C、when setting the value of a field , the formula must be in the field‟s input validation event
- D、the formula does not specify that title is an existing field. Thus it is interpreted as a temporary variable
正确答案:D
第3题：
My little brother used to be afraid of the dark．（改为反意疑问句）
My little brother used to be afraid of the dark，_____ _____?
38. didn't he
第4题：
第5题：
You are developing a Windows Forms application that contains a DataGridView control. The DataGridView capture the customer's name, address, and phone number. You have been asked to provide data validation in a DataGridView to prevent users from leaving the.. You need to ensure that users cannot tab out of the name field without entering data What should you do ?（）
- A、 Validate the name field in the CellValidating event. Set e.Cancel = true if the name field is
- B、 Validate the name field in the CellErrorTextChanged event. Get e.RowIndex if the name field ..
- C、 Validate the name field in the CellEnter event. Set the focus on the name field if the name ...
- D、 Validate the name field in the CancelRowEdit event. Set the focus on the name field if the name ...
正确答案:A
第6题：
Which of the following statements is NOT true?（）
- A、The open field system provided a good opportunity to experiment.
- B、The open field system wasted land.
- C、The open field system was wasteful of labor and time.
- D、The open field system made livestock farming difficult.
正确答案:A
第7题：
jim has created a field hint for the address field. Users tell him this text disappears when they click in the address field. which one of the following is most likely reason?（）
- A、 the address field is computed
- B、 jim should have used a text popup
- C、 jim stored the field hint in the database
- D、 field hint only display when the user has not clicked in the field （field hint）
正确答案:D
第8题：
Dark Forces Dominate Universe
The earth,moon,sun and all visible stars in the sky make up less than one percent of
the universe.Almost all the rest is dark matter and dark energy,unknown forces that
_______(1)astronomers.
Observations in recent years have changed the basic_______(2)of how the
universe evolved and have indicated how little is known about the major forces and
substances that_______(3)our world.
Astronomers now know that luminous（发光的）matter一stars , planets and hot gas一
accounts_______(4)only about 0.4 percent of the universe.Non-luminous
components , such as black holes and intergalactic（星系间的）gas,_______(5)
up 3.6 percent.The rest is either dark matter,about 23 percent,or dark energy,about
73 percent.
Dark matter,sometimes_______(6)"cold dark matter,"has been known for some time.Only recently have researchers come to understand the key role it_______ (7)in the formation of stars,planets and even people.
"We_______(8)our very existence to dark matter,"said physicist Paul
Steinhardt and a co-author of a review on dark matter which_______(9)not long ago
in the journal Science.
"Dark matter dominated the structure_______(10)in the early universe,"
Steinhardt said."For the first few billion years dark matter contained most of the mass of the
universe. You can think of ordinary matter_______(11)a froth（泡沫）of an ocean
of dark matter. The dark matter clumps（结成块）and the ordinary matter falls into it. That
_______(12) to the formation of the stars and galaxies（星系）."
Without dark matter,"there would be virtually no structures in the universe,"
The nature of dark matter is_______(13).It cannot be seen or detected
directly. Astronomers know it is there because of its_______(14) on celestial（天体
的）objects that can be seen and measured.
But the most dominating force of all in the universe is called dark energy,a recently
________(15)power that astronomers say is causing the galaxies in the universe to
separate at a faster and faster speed.
A:with
B:as
C:from
D:beside
第9题：
第10题：