1`I received a letter from my brother with an usual stamp on

1`I received a letter from my brother with an usual stamp on which( )my collection of stamps.
A added up to
B added to
C added in
D added together
2 On cold winter morning,we always find it hard to get our cars ( )
A started
B starting
C to start
D A or C
3 In big cities,cleaning women get paid by the hour.这一句里的“paid”能不能改成“to be paid

第一个选B added up to和added together都是 总计 的意思
added in是把.加进去 的意思显然需要用被动 而且也不是省略句 选 项的时态是和前面一样的 一般过去式 若选
added in前面应该加was
第二个选A 车子被启动 而且 started是一种状态get 相当时联系动词
start是及物动词所以C不行吧
第三个to be 有将来时的意思 这里所表示的只是一种现象应该不需要用吧