The water in the ________(河流) is clean.
【答案】river
【解析】河流是单词river, 在河里用单数即可, 故应填river.
题目：The water in the ________(河流) is clean.
关键字：
The water in the ________(河流) is clean.
【答案】river
【解析】河流是单词river, 在河里用单数即可, 故应填river.