Suppose two random variables [图] and [图] have a ...

Supposeand,, then

A、is concave up on.

B、is concave down on.

C、has a critical point.

D、is decreasing on.

Suppose, find.

A、

B、

C、

D、

For this part ，you’re allowed 30 minutes to write an essay. Suppose you have two options upon graduation: one is to find a job somewhere and the other to start a business of your own. You are to make a decision. Write an essay to explain the reasons for your decision. You should write at least 120 words but no more than 180 words.

Suppose you have invited Laura to your birthday tea party. But there is some emergency and you have to cancel the party. Write her a note to 1) cancel the invitation, and 2) explain why. You should write about 100 words. Do not use your own name. Use "Li Ming" instead.

Part A 66. Suppose that you have been a regular of a hotel for many years. But during the last 2days, the air-conditioner didn t work and nobody came to clean your room. Write a letter of com-plaint to the hotel manager. Your letter should include: 1 ) a description of the situation2) complaint about the situation3) your request You should write approximately 100 words. Do not sign your own name at the end of your letter, use "Wang Lin" instead. You dont need to write the address.

Directions: For this part, you are allowed 30 minutes to write an essay. Suppose you have two options upon graduation: one is to find a job somewhere and the other to start a business of your own. You are to make a decision. Write an essay to explain the reasons for your decision. You should write at least 120 words but no more than 180 words.

Suppose we have the relation schema R(A,B,C,D)with functional dependencies ;F{A→ B,B→C,C→D,D→A},then R(A,B,C,D)at least is in

A．1NF

B．2NF

C．3NF

D．BCNF

Suppose that in Experiment 2, two hours after the completion of Trial 5, the students had measured the roll time of the can of liquid without first shaking the can.Based on the results of Trials 4 and 5, the roll time would most likely have been:

A.less than 1.86 sec.

B.between 1.86 sec and 1.93 sec.

C.between 1.94 sec and 1.96 sec.

D.greater than 1.96 sec.

16. Supposeis continuous on [0,2] and differentiable on (0,2),, andfor all. Which is the lowest possible value of?

A、(A) 2

B、(B) 0

C、(C) 1

D、(D) None of above

Suppose we have the relation schema R(A,B,C,D)with functional dependencies;F{A→B,B→C,C→D,D→A},then R(A,B,C,D)at least is in

A．1NF

B．2NF

C．3NF

D．BCNF