What are two central ideas of the text? A
There is a widespread need for an artificial blood substitute.
B
Developing safe and reliable alternatives for human blood is challenging.
С
An essential function of blood is to transport oxygen throughout the body.
D
Scientists are struggling to evaluate the effectiveness of using artificial blood for
transfusions.
E
A hemoglobin-based oxygen carrier has been approved to treat patients needing blood
transfusions in South Africa.
F
The lack of advancement in medical technology prevents doctors from treating patient
in need when blood transfusions are not possible.

Public opinion polls are used in marketing

Boss: oh no! that’s the phone again! secretary: blank boss: . a. shall i take it? b. will you answer it? c. can you do me a favor? d. may i hang it up?

[1] nothing that comes from the desert expresses its extremes better than the unhappy growth of the tree yuccas. tormented, thin forests of it stalk drearily in the high mesas, particularly in that triangular slip that fans out eastward from the meeting of the sierras and coastwise hills. the yucca bristles with bayonet-pointed leaves, dull green, growing shaggy with age like an old [5] man's tangled gray beard, tipped with panicles of foul, greenish blooms. after its death, which is slow, the ghostly hollow network of its woody skeleton, with hardly power to rot, makes even the moonlight fearful. but it isn't always this way. before the yucca has come to flower, while yet its bloom is a luxurious, creamy, cone-shaped bud of the size of a small cabbage, full of sugary sap. the indians twist it deftly out of its fence of daggers and roast the prize for their [10] own delectation why does the author use the words "bayonet-pointed" (line 4) and "fence of daggers" (line 9) to describe the leaves of the yucca tree? . to create an image of the sharp edges of the plant to emphasize how beautiful the plant's leaves are to explain when and where the plant grows to show how afraid the author is of the plant