题干
.
A lot of tents, drinking water and food __________ to the homeless earthquake survivors in the past several weeks.
A lot of tents, drinking water and food __________ to the homeless earthquake survivors in the past several weeks.
A：are sent
B：were sent
C：have been sent
D：had been sent
答案(点此获取答案解析）
C
的前
项和为
，且
，则
等于
