![](https://cos-cdn.shuashuati.com/pipixue-web/2020-1231-2005-12/ti_inject-812ce.png)
设 N , Z , R 分别表示自然数集、整数集和实数集,下列关系中能构成函数的是
A.
p.p1%20%7Bmargin%3A%200.0px%200.0px%200.0px%200.0px%3B%20text-align%3A%20justify%3B%20font%3A%2010.5px%20%26%2339%3BTimes%20New%20Roman%26%2339%3B%3B%20color%3A%20%23ff0000%7D { >|( x, y ∈ N )∧( x + y <10)}
B.
{ >|( x, y∈ R )∧ ( y = x 2 )}
C.
{ >|( x, y ∈ R )∧ ( y 2 = x )}
D.
{ >|( x, y ∈ Z ) ∧ ( x ≡ y (mod 3)}