Read the following passage and mark the letter A, B,C, or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks from 24 to 33.

An endangered species is a species (24)_______ population is (25) _______small that it is in danger of becoming extinct. Many countries have laws offering special protection to these species; (26) _______, forbidding hunting (27)_______ banning their sales. Only a few of the many truly endangered species actually make it to the lists and obtain legal protection. Many more species become extinct, or potentially become extinct, without gaining public notice.

Many of these laws are (28) _______. Typical areas of controversy include: criteria for placing a species on the endangered species list, and criteria for removing a species (29)_______ the list once its population has recovered.

A listing as an endangered species can backfire, as it (30)_______ a species more valuable and more desirable for collectors and poachers.

The conservation status of a species is an indicator of the (31)_______of that endangered species continuing to survive. Many factors are taken (32)_______ account when assessing the conservation status of a species: not simply the number remaining, but the overall increase or decrease in the population over time, breeding success rates, known threats, and so on.

The best-known worldwide conservation status listing is the World Conservation Union Red List. (33)_______ , many more specialized lists exist

Điền vào ô số 24

A. whom 

B. that 

C. who 

D. whose

\(A=\frac{\left(\sqrt{x}+\sqrt{y}\right)^2}{\sqrt{x}\left(\sqrt{x}+\sqrt{y}\right)}.\frac{\left(\sqrt{x}-\sqrt{y}\right)^2}{\sqrt{y}\left(\sqrt{x}-\sqrt{y}\right)}=\frac{\sqrt{x}+\sqrt{y}}{\sqrt{x}}.\frac{\sqrt{x}-\sqrt{y}}{\sqrt{y}}=\frac{x-y}{\sqrt{xy}}\)

Cho biểu thức  B   =   16 x + 16 - 9 x + 9 + 4 x + 4 + x + 1

với x ≥ -1.

Tìm x sao cho B có giá trị là 16.