New traffic rules that took effect on January l, 2013 are much stricter______ than          in the past．

With the weather getting colder, visitors from Australia spent their ___ days in Beijing.　    

Here is       example,which shows that petroleum is a very important industrial material.

Being a parent is not always easy and being the parent of a child with special needs often carries with _____extra stress.

How long do you think ___________ the Microsoft brings out a new product?