问题
Sam ______ coins since he was eleven years old, and now he has hundreds of them.
A:collected
B:had collected
C:has been collecting
D:had been collecting
B:had collected
C:has been collecting
D:had been collecting
正确答案是：
同类题型
Clothes made of silk ________ softer than those made of cotton.
“How long does it take you ________to Beijing?” “More than three hours.”
There is usually ________ in summer in Yangzhou, it helps crops(庄稼) grow well.
All the students in Class One went to the cinema Li Ping. Why?—Because he had a stomachache.[ ]