______is known to us all, only the theory ______ on practice can be practical.
| A．Which; base | B．Which; based | C．As; based | D．As; basing |
（届安徽省安庆市高三第二次模拟考试英语试卷）
_____ there was no conclusive evidence, most people thought he was guilty.
| A．Since | B．While | C．When | D．However |
（届江苏省淮州中学高三3月份模拟英语试卷）
It’s a common scene in the film Tangshan Earthquake that families cry helplessly over _____ is left of their homes.
| A．what | B．which | C．there | D．it |
（届福建省泉州市高三质检英语试卷）
As the interview rule goes，you can take some time to think through answers_______ you make a reply.
| A．after | B．when | C．before | D．since |
（届北京市东城区普通校高三3月联考英语试卷）
Don’t be afraid of asking for help ___________ it is needed.
| A．unless | B．since | C．when | D．although |
（届重庆市南开中学高三二诊模拟英语试卷）
Parents are advised to put books __________ they are easily accessible to children .
| A．which | B．where | C．in which | D．who |