He began to take political science ________ only when he left school. 

 Nature reserves are very important for preserving many animals and plants, which would _______ run the risk of becoming extinct.

 I won’t buy the house, which was too expensive and too big. ______, I’d grown fond of our little rented house.

He has impressed his employers considerably and _____ he is soon to be promoted.

She seems_     happy in her new job since there is nothing troublesome to bother her.