Lots of rescue workers were working around the clock, _______ supplies to Yushu, Qinghai Province after the earthquake. [ ]

____ all of you are top students, only one will be chosen for the coming competition.

If it , we will go hiking at Cool City Park.

What’s ___ matter with you-I have ___ stomachache.

Jack could have avoided that terrible car accident, but he ________ careful enough