下载APP
举一反三
【单选题】图5-6为影响农作物生产因素示意图，正确的是( ) 图5-6
A.
①花生②水稻③蔬菜④冬小麦
B.
①甘蔗②棉花③花卉④甜菜
C.
①油菜②花卉③水果④棉花
D.
①棉花②桑树③亚麻④冬小麦
【单选题】For the (26) month, mysterious falls of large chunks of ice (冰雹) (27) rained down on Spain and Italy. Juana Sanchez, a 70-year-old woman in Almeria, southern Spain, was knocked (28) when she was struc...
A.
Although eyewitnesses to the phenomenon report that they did not see anything in the sky that could account (44) the ice, scientists had to come up with a rationalization. Professor Jesus Martinez Frias, the geologist investigating the ice falls in Spain, told BBC News that the ice pieces had probably been (45) through sudden temperature drops in the stratosphere. This was the most likely explanation, he said, for the "very unusual" phenomenon.
【单选题】通过哪种方式可以减少金属镉向农作物的转移
A.
加入石灰使pH增加，使其转化成难溶盐
B.
加入Ca(OCl)Cl使pH增加，转化成难溶盐
C.
加入硅酸使pH降低，转化成难溶盐
D.
加入CaCl 2 使pH降低，转化成难溶盐
E.
加入NaCl与镉元素结合