问题 选择题

下列地区中,水循环最活跃的是

A.南极地区

B.亚马孙平原

C.长江流域

D.澳大利亚中西部

答案

B

本题考查水循环的主要环节。水循环主要环节有:蒸发、降水、水汽输送、地表径流、下渗、地下径流、植物蒸腾等。一般来说,海水温度越高,蒸发量越大,海—气间的水分交换也较为活跃。亚马孙平原位于赤道地区,温度高,海水蒸发快,降水多,地表径流大,所以水循环最活跃。所以本题选择B选项。

选择题
单项选择题

Young girls at high risk for depression appear to have a malfunctioning reward system in their brains, a new study suggests. The finding comes from research that (1) a high-risk group of 13 girls, aged 10 to 14, who were not depressed but had mothers who (2) recurrent depression and a low-risk group of 13 girls with no (3) or family history of depression. Both groups were given MRI brain (4) while completing a task that could (5) either reward or punishment.

(6) with girls in the low-risk group, those in the high-risk group had (7) neural responses during both anticipation and receipt of the reward. (8) , the high-risk girls showed no (9) in an area of the brain called the dorsal anterior cingulated cortex (背侧前扣带皮质), believed to play a role in (10) past experiences to assist learning.

The high-risk girls did have greater activation of this brain area (11) receiving punishment, compared with the other girls. The researchers said that this suggests that high-risk girls have easier time (12) information about loss and punishment than information about reward and pleasure.

"Considered together with reduced activation in the striatal (纹状体的) areas commonly observed (13) reward, it seems that the reward-processing system is critically (14) in daughters who are at elevated risk for depression, (15) they have not yet experienced a depressive (16) ," wrote Ian H. Gotlib, of Stanford University, and his colleagues. " (17) , longitudinal studies are needed to determine whether the anomalous activations (18) in this study during the processing of (19) and losses are associated with the (20) onset of depression," they concluded. The study was published in the April of the Archives of General Psychiatry.

16()

A.anecdote

B.time

C.episode

D.process