Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions.

Fish that live on the sea bottom benefit by being flat and hugging the contours. There are two very different types of flatfish and they have evolved in very separate ways. The skates and rays, relatives of the sharks have become flat in what might be called the obvious way. Their bodies have grown out sideways to form great “wings” They look as though they have been flattened but have remained symmetrical and “the right way up”. Conversely fish such as plaice, sole, and halibut have become flat in a different way. There are bony fish which have a marked tendency to be flattened in a vertical direction; they are much “taller” than they are wide. They use their whole vertically flattened bodies as swimming surfaces, which undulate through the water as they move. Therefore when * their ancestors migrated to the seabed, they lay on one side than on their bellies. However, this raises the problem that one eye was always looking down into the sand and was effectively useless - In evolution this problem was solved by the lower eye “moving” around the other side. We see this process of moving around enacted in the development of every young bony flatfish. It starts life swimming near the surface, and is symmetrical and vertically flattened, but then the skull starts to grow in a strange asymmetrical twisted fashion, so that one eye for instance the left, moves over the top of the head upwards, an old Picasso - like vision. Incidentally, some species of 20 flatfish settle on the right side, others on the left, and others on either side

It can be inferred from the passage that horizontal symmetrical fish:

A. have one eye each side of the head

A. have one eye each side of the head

C. have two eyes on top of the head

D. have eyes that move around the head

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 30 to 3 4.

In Africa, people celebrate with joy the birth of a new baby. The Pygmies would sing a birth-song to the child. In Kenya, the mother takes the baby strapped to her back into the thorn enclosure where the cattle are kept. There, her husband and the village elders wait to give the child his or her name.

In West Africa, after the baby is eight days old, the mother takes the baby for its first walk in the big, wide world, and friends and family are invited to meet the new baby. In various African nations, they hold initiation ceremonies for groups of children instead of birthdays. When children reach a certain designated age, they learn the laws, beliefs, customs, songs and dances of their tribes. Some African tribes consider that children from nine to twelve are ready to be initiated into the grown up world. They may have to carry out several tests.

Maasai boys around thirteen years old to seventeen undergo a two-stage initiation. The first stage lasts about three months. The boys leave their parents' homes, paint their bodies white, and are taught how to become young warriors. At the end of this stage, they have their heads shaved and they are also circumcised. At the second stage, the young warriors grow their hair long and live in a camp called a “manyatta” where they practice hunting the wild animals that might attack the Maasai herds. This stage may last a few years. When they are ready, they will marry and become owners of large cattle herds like their fathers. The girls are initiated when they are fourteen or fifteen. They are taught by the older women about the duties of marriage and how to care for babies. Soon after that they are married and lead a life similar to that of their mothers

What does the passage mainly discuss? 

A. Celebrations in Africa

B. Birthday ceremonies for children in Africa 

C. Traditions of Maasai people when having a new baby 

D. Activities in a birth celebration

Hỗn hợp X gồm metyl fomat, đimetyl oxalat và este Y đơn chức, không no (có hai liên kết pi trong phân tử), mạch hở. Đốt cháy hoàn toàn 0,5 mol X cần dùng 1,25 mol O₂ thu được 1,3 mol CO₂ và 1,1 mol H₂O. Mặt khác, cho 0,4 mol X tác dụng vừa đủ với dung dịch NaOH, thu được dung dịch Z (giả thiết chỉ xảy ra phản ứng xà phòng hóa). Cho toàn bộ Z tác dụng với lượng dư dung dịch AgNO₃ trong NH₃, đun nóng. Sau khi các phản ứng xảy ra hoàn toàn, khối lượng Ag tối đa thu được là 

A. 43,2 gam. 

B. 86,4 gam

C. 108,0 gam. 

D. 64,8 gam.

Chứng minh rằng với n   ∈   N * , ta có đẳng thức:  1 2   +   1 4   +   1 8   +   . . .   +   1 2 n   = 2 n - 1 2 n

Prices quoted in this package include _____ hours of Internet access for one month.

A. unwarranted      

B. uncontrolled

C. unlimited

D. unrecoverable

Một điện tích điểm q = - 2 , 5 . 10 - 7 C đặt tại điểm M trong điện trường, chịu tác dụng của lực điện trường có độ lớn 6 , 2 . 10 - 2 N. Cường độ điện trường tại M là:

A.   2 , 4 . 10 5 V / m                         

B.  - 2 , 4 . 10 5 V / m

C.  15 . 10 - 9 V / m

D.  - 15 . 10 - 9 V / m

Cho các polime: polietilen, xenlulozơ, protein, tinh bột, nilon-6, nilon-6,6, polibutađien. Dãy các polime tổng hợp là

A. Polietilen, polibutađien, nilon-6, nilon-6,6.

B. Polietilen, xenlulozơ, nilon-6, nilon-6,6.

C. Polietilen, tinh bột, nilon-6, nilon-6,6.

D. Polietilen, nilon-6, nilon-6,6, xenlulozơ.