问题
选择题
--- You look ______,Paul. What’s the matter?--- I’m having trouble ______ math.
A．tired, to learn
B．worried, learning
C．frustrated, to learn
D．angrily, learning
答案
答案：B
B 根据句意得知，Paul因不会数学题而显得担心、忧虑。故第一个空填worried；固定句型have trouble (in) doing sth.“做某事有困难”，故选B。