[单项选择]Why will a switch never learn a broadcast address?（）
A. Broadcast frames are never sent to swiches.
B. Broadcast addresses use an incorrect format for the switching table.
C. A broadcast address will never be the source address of a frame.
D. Broadcasts only use network layer addressing.
E. A broadcast frame is never forwarded by a switch.

[单项选择]Why will as witch never learn a broadcast address？（）
A. Broadcast frames are never sent to swiches.
B. Broadcast addresses use an incorrect format for the switching table.
C. A broadcast address will never be the source address of a frame.
D. Broadcasts only use network layer addressing.
E. A broadcast frame is never forwarded by a switch.

[单项选择]Why will a switch never learn a broadcast address?（）
A. Broadcasts only use network layer addressing.
B. A broadcast frame is never forwarded by a switch.
C. A broadcast address will never be the source address of a frame.
D. Broadcast addresses use an incorrect format for the switching table.
E. Broadcast frames are never sent to switches.

[单项选择]You never told me why you were late for the meeting, ______

[单项选择]You never told us why you were late for the party, ______

[单项选择]You never told us why you were late for the last meeting, ______

[单项选择]Why does Mr. Smith never de any housework

[单项选择]Why do some people say that they never dream A. They forget all of their dreams. B. They wouldn't like to tell the truth. C. They cannot enjoy their free time.

[单项选择]Why does the man say he will never fly with this airline again _____
A. Because of the bad service here.
B. Because it is very clouded here.
C. Because it is not safe with this airline.
D. Because there are always problems.

[单项选择](He's) a timid fellow. (That's) why he (never) (dare) to protest.
A. He’s
B. That
C. never
D. dare

[单项选择]-- Why are you staring -- I've never seen_______tree before.
A. kind of
B. that kind of
C. such kind
D. such

[单项选择] Learn from Mistakes You can only learn from a mistake after you （1） you’ve made it. As soon as you start blaming other people (or the universe itself) you distance yourself （2）any possible lesson. But if you courageously stand up and honestly say “This is my mistake and I am responsible” the possibilities for learning will move towards you. Admission of a mistake, even if only privately to yourself, makes learning （3）by moving the focus away from blame assignment and towards understanding. This advice （4）counter to the cultural assumptions we have about mistakes and failure, namely that they are （5） things. We’re taught in school, in our families, or at work to feel guilty about failure and to do whatever we can to （6）mistakes. This sense of shame explains why many people give up on their goals: they’re not （7） for the mistakes and failures What’s missing in many people’s beliefs about success is the fact that the more （8）the goal, the more frequent and difficult setbacks will be. The larger your ambitions, the more dependent you will be on your ability to overcome and learn from your mistakes. But for many reasons admitting mistakes is difficult. An implied value in many cultures is that our work represents us: if you fail a test, then you are a （9）. If you make a mistake then you are a mistake. Learning from mistakes requires three things: putting yourself in situations where you can make interesting mistakes; having the self-confidence to admit to them; being （10）about making changes. （6）内应选（）
A. runs
B. access
C. challenging
D. shameful
E. courageous
F. possible
G. admit
H. failure
I. avoid
J. prepared
K. activities
L. from