问题 选择题
已知
a
=(2,-1,2),  
b
=(2,2,1)
,则以
a
b
为邻边的平行四边形的面积为(  )
A.
65
B.
65
2
C.4D.8
答案

设向量

a
b
的夹角是θ,则由向量的数量积和题意得,

cosθ=

a
b
|
a
| |
b
|
=
4-2+2
4+4+1
4+1+4
=
4
9

∴sinθ=

1-
16
81
=
65

∴以

a
b
为邻边的平行四边形的面积S=2×
1
2
×|
a
|×|
b
65
=
65

故选A.

选择题
阅读理解

阅读理解.

     Angelina Jolie is a famous movie star. She is also know as a mother of three children.

     On March 10, 2002, Angelina Jolie adopted (领养)her first child, Maddox, whom

Jolie usually calls "Mad". Maddox got a lot of public attention and was named "the cutest

(聪明/漂亮的) celebrity (著名人士)kid by a famous magazine.

     On July 6, 2005, Jolie adopted a six-month-old girl named Zabara, which means "flower".

Her birth mother died of AIDS and her rather is unknown.

     On May 27, 2006, Jolie gave birth to a daughter named Shiloh, which means "the

peaceful one". As the child of Angelina Jolie and Brad Pitt, the girl got a lot of attention. The

parents altogether collected $10 million from parts of the world for their daughter's photos.

All the money was given to a charity.

     As early as 2001, while Jolie was filming Tomb Raider 《古墓丽影》in some poor

areas, she worked as a UN Goodwill Ambassador. She visited poor people, helped

homeless children and gave money to those who were in trouble or homeless. She has done

a lot for those who need help.

     Mother love is great. But what is greater is the love for people all over the world.

1. Of all the three children, Angelina Jolie ________.

A. gave birth to none B. only gave birth to one

C. is the natural mother of two D. is the natural mother of all

2. According to the passage, the greatest persons are ________.

A. mothers

B. those who have adopted homeless children

C. those who have been working for people all over the world.

D. none of the above

3. Which of the following is NOT TRUE?_______.

A. Maddox is Angelina Jolie's first adopted child.

B. Zahara's father died of AIDS.

C. Shiloh is the child of Angelina Jolie and Brad Pitt.

D. In 2001, Jolie filmed Tomb Raider.