[填空题]Peak military spending in 1944 was more than 70% of prewar gross domestic product.

[填空题]Peak military spending in 1944 was more than 70% of prewar gross domestic product.

[填空题]Complete the notes below.
Choose NO MORE THAN ONE WORD from the passage for each answer.
Write your answers in boxes 8-13 on your answer sheet.
Up to 1940 More mammals and birds exhibited than 8 (9) were very popular animals in many zoos at one time.
1940s and 1950s Zoos started exhibiting animals according to their (10) and where they came from.
1960s Some zoos categorised animals by (11)
1970s (12) were employed following protests about animal care.
1980s onwards The importance of (13) became greater.

[单项选择]Mycorrhizal fungi infect more plants than do any other fungi and are necessary for many plants to thrive, but they have escaped widespread investigation until recently for two reasons. First, the symbiotic association is so well-balanced that the roots of host plants show no damage even when densely infected. Second, the fungi cannot as yet be cultivated in the absence of a living root. Despite these difficulties, there has been important new Work that suggests that this symbiotic association can be harnessed to achieve more economical use of costly superphosphate fertilizer and to permit better exploitation of cheaper, less-soluble rock phosphate. Mycorrhizal benefits are not limited to improved phosphate uptake in host plants. In legumes, mycorrhizal inoculation has increased nitrogen fixation beyond levels achieved by adding phosphate fertilizer alone. Certain symbiotic associations also increase the host plant’s resistance to harmful root fungi. Whether this resistance results from
A. a description of a replicable experiment
B. a refutation of an earlier hypothesis
C. a summary report of new findings
D. a confirmation of earlier research