A、Her knees were injured. B、Her foot were wet. C、She was tired. D、The sand was hot. CWhy did the woman have to stop playing in t

M: Hey, Lily. Seems you got some sun this vocation.
W: Yeah, you may say so. I spent the vocation at the beach.
M: Oh, yeah? That’s great! Where did you stay?
W: Some friends of mine live out there. And they invited me for as long as I wanted to stay.
M: So, what are you doing back here already?
W: Oh, I have a research project waiting for me. And I just couldn’t do any serious studying at the beach.
M: I guess so. Well, what did you do out there? I mean, besides lie out in the sun, obviously.
W: I walked my friend’s dogs along the beach and I played some volleyball. You know, I never realize how hard it is to run on sand. I couldn’t even get through a whole game before I had to sit down. It’s much easier to run on the wet sand near the water.
M: Did you go swimming?
W: I wanted to, but they said the water wasn’t warm enough for that until a couple of months from then on. So I just wetted in up to my knees.
M: It all sounds so relaxing. I wish I could get away to the beach like that.
W: Of course you could. Don’t tell me you spent the vocation in the library again.