Xác định độ dài các trục, tọa độ các tiêu điểm, tọa độ các đỉnh của elip có phương trình sau:  4 x 2   +   9 y 2   =   1

Mark the letter A, B, C, or D on your answer sheet to show the underlined part that needs correction in each of the following questions.

In a critical review of an experiment, a researcher should question (A) the validity,(B) the reliable,(C) and the importance (D) of any test results

A. question

B. validity

C. the reliable

D. importance

Read the following passage and mark the letter A, B, C, or D to indicate the correct word for each of the blanks. Fill in the appropriate word in question 33

           Nearly 200 of the 1500 native plant species in Hawaii are at risk of going extinct in the near future because they have been  (33)_______ to such low numbers. Approximately 90 percent ofHawaii's plants are found nowhere else in the world but they are  (34)_______  by alien invasive species such as feral goats, pigs, rodents and  (35)_______ plants.

          The Hawaii Rare Plant Restoration Group is striving to (36)_______  the extinction of the 182 rare Hawaiian plants with fewer than 50 individuals remaining in the  (37)_______ . Since 1990,  (38)_______ a result of their "Plant Extinction Prevention Program", sixteen species have been brought into  (39)_______ and three species have been reintroduced. Invasive weeds have been removed in key areas and fencing put up in order to  (40)_______  plants in the wild.

            In the future the Hawaii Rare Plant Restoration Program aims  (41)_______  collecting genetic material from the remaining  plants  in  the  wild  for storage  as a safety net for the future. They also aim to manage wild populations and where possible reintroduce species into (42)_______  .

A. developed

B. reduced

C. disappeared

D. increased