由于伦理方面的原因,目前尚未在人类身上成为现实的辅助生殖技术是
A.代孕技术
B.同源人工授精
C.异源人工授精
D.无性生殖
E.体外受精
参考答案:D
Health officials in western Siberia are to begin in slaughter of thousands of birds today after identifying Russia’s first outbreak of a bird flu strain that can be fatal in humans. Doctors in neighboring Kazakhstan have also (1) that a 19-year-old poultry worker (2) admitted to hospital with (3) of bird flu, only to be diagnosed (4) double pneumonia. The H5N1 strain of avian (5) has killed 60 people (6) 2fib in Vietnam, Thailand, Cambodia and Indonesia, but has rarely been found in birds or humans (7) Asia. Health officials (8) that HSN1 is infecting migrating birds, which could spread the (9) into Europe. Earlier this year China registered the first outbreak of H5N1 (10) wild birds, some of which (11) to breeding grounds in Siberia. These birds could come (12) contact with others flying to Europe and North America. Russia’s (13) began in the Novosibirsk (14) , about 1,750 miles (15) of Moscow in the Asian part of Russia, early last month, but the veterinary service (16) the virus only last week. Valery Mikheyev, the chief sanitary doctor of Novosibirsk, said that teams had been (17) the (18) birds and supervising the slaughter in13 (19) villages. He said, "The state of (20) of the inhabitants of these areas gives (21) cause for alarm. Up to 6,000 people are being (22) per day.The virus seems to have (23) only private farms that let (24) mix with wild birds. Further outbreaks were registered in the Omsk and Altai regions, but the strain had (25) to be determined, Russia’s Emergency Situations Ministry said.
简易沤肥技术是指将人粪尿、不能食用的烂叶子、动物粪便、杂草、秸秆、废物垃圾等有机废物混合堆积、糊泥密封,在自然条件下利用(),使堆料中的有机物腐熟,达到土壤可接受的稳定程度。
A.细菌的作用
B.有机物自身作用
C.土壤的天然稳定作用
D.微生物的发酵作用