单项选择题
F: Thomas is absent from his class today. Do you know what happens to him
M: I heard he has caught a severe cold. He must be in bed by now.
F: Has he been to the hospital He’s got to be careful, for there is a flu these days in the city.
M: Sure, I am calling to tell him to be careful.
F: We’d better buy some fruit and pay him a visit.
A．Go to see Thomas.
B．Give him a call.
C．Tell him to be careful.