Protective clothing must be worn when the machine is in _________.

(2013·安徽蚌埠二检)Could it be in the restaurant ________ you had dinner with me yesterday ________ you lost your handbag?

inese agricultural tax wasn’t completelyabolished______2006, which reduced the farmers’ burden greatly.

The camera you mentioned is of high quality, but it is _______ expensive a camera _______ I can’t afford.

The manager _______ the workers how to improve the program since 9 a.m