To keep safe _______ an earthquake, you should remain at a spot in your room where nothing may fall on you.
______ the growing number of patients, the clinic had to extend its service from five days to seven days a week.
It remains ______ whether she’ll be fit enough to play in the finals.
Dad had to cycle to work this morning because his car _______ at the garage.
John passed the examination though he had only spent _______ on the subject as others had done.
He started to work dilligently _____ he came up with the idea of hybrid rice for the first time in the 1960’s.