锅炉进行外部检验、内部检验、水压试验的时间间隔为( )。
A.每年、每两年、每六年
B.每两年、每年、每六年
C.每六年、每两年、每年
D.每两年、每六年、每年
参考答案:A
如图,是肺泡与血液之间的气体交换示意图,请据图回答下列问题:
(1)肺泡外面包绕着丰富的[③]______,并且肺泡壁和毛细血管壁都是由______层扁平的上皮细胞构成,这样的结构特点适于______与______之间进行气体交换.
(2)图中A过程表示______(填“氧气”或“二氧化碳”)从肺泡扩散进入血液;B过程表示______(填“氧气”或“二氧化碳”)从血液扩散进入肺泡.
Today, we’ll talk about what other effects watching TV might produce on children. Children should be (1) a lot of television, many experts and parents agree, but there is at least one circumstance when it might be beneficial: (2) . A recent study conducted by Italian researchers found that children (3) immediately preceding and during blood tests experienced less pain than children whose mothers (4) during the procedure, or children whose mothers were present but (5) .The research, led by Carlo Brown, MD, at the University of Siena, is published in the Archives of Disease in Childhood. (6) the study. None received any type of anesthesia; the children and their mothers (7) . Both the group whose mothers attempted to distract them from the blood tests and those whose mothers simply observed reported (8) than the group who watched cartoons. For that group, the levels of pain were less and the children were better able to (9) .One of the possible explanations is that children might have (10) during the procedures, exacerbating their perception of pain. "The higher pain level reported by children during (11) shows the difficulty mothers have in interacting positively (12) in their children’s life," the authors write.However, they stressed that (13) still provided benefits, noting that the children would (14) during the procedures. "Indeed, children state that having their parent present (15) when in pain," say the authors.Another possibility offered for consideration is the notion that the (16) might release pain-quelling endorphins. Endorphins, (17) produced by the pituitary gland, resemble opiates in their ability to produce analgesia and a sense of well-being. In other words, they might (18) .In any case, the study results suggest that health workers should (19) to watch television during painful procedures (20) .