3.酸雨是指Ph<( )的降水
A. 4.5
B. 5.5
C. 5.6
D. 6.5
人类活动产生的污染物或污染因素,进入环境的数量超过( )时,就会导致环境质量恶化,出现环境污染。
A. 环境现状
B. 环境容量
C. 环境浓度
When we talked about the correlation between language and culture, it is said that langue is an indispensable ________ of culture. Culture finds a better representation through language use.
A. tool
B. application
C. carrier
D. none of the above
The term category is used to refer to a group with certain features in _________ and we can think of the vocabulary we learn as an inherited set of category labels.