______ is it that metals plays such an important part in our daily life?

It is a good habit to______ your school things afterfinishing your homework.

We’regoingto______withsomefriendsforapicnic.Wouldyouliketojoinus?

I called the airline to _____ my flight reservation a weekbefore I left for Canada. [ ]

Not only I but also Jane and Mary ______tried ofhaving one examination after another.