No one can avoid ______ by advertising; it is everywhere. 

(2013·山西四校二模)Studies show that students often ________ to too much pressure tend to develop mental problems.

Any packet __   properly will not be accepted by the post office．

 The maker of the popular game Angry Birds announced on Tuesday that it would open its first overseas operation in Shanghai, _____ a clear step to further enter the booming Chinese market. 

The traffic rule says young children under the age of five and _______ less than 25 kilograms must be in a child safety seat.