These machines can help recycle the waste which would ______be thrown away.

However weak we are，we can still do something against the powerful nature so long as we are     prepared．

Polar bears live      on sea ice，which they use as a platform for hunting seals

It is generally believed that a successful Olympic Games            relies on well-performed IT services.

Progress so far has been very good.We are________confident that the work will be completed on time.