当人在做某件事情是失败时，常常要去寻找原因，能够激发动机的归因是（）
A．任务难度大
B．努力不够
C．运气不好
D．能力不够
参考答案：B
张骞两次出使西域的时间分别为公元前_______年和公元前_______年。
When I got home last night, I was frightened to find that in front of my door_____ . [ ]
A. was seated a large dog
B. sat a large dog
C. was a large dog seated
D. did a large dog sit
