问题补充:
--- 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:
A. tired, to learn
(答案→)B. worried, learning
C. frustrated, to learn
D. angrily, learning
解析: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。