问题
填空题
根据句意及首字母提示完成下列句子
1. The boys often help the old man c_____water and sweep the floor.
2. I come here s _____ to ask you a question.
3. The glass is f_____with water.
4. He can't hear anything because he is d_____.
答案
1. carry 2. specially 3. filled 4. deaf
The number of tuples that the result of the expression R co S (Here is the natural join of relations R and S) is