She _____________________ have studied harder, but she was too lazy.

Please do not come to my house before six. I ________________ before then.

_______________ you watched the film I told you about?

Everyday, our rubbish___________ collected from outside our homes.

He ______________ have arrived earlier, but he missed the bus.

You have finished your exams and school _____________________ up for the holidays.

Medicines have been developed from rain forests plants for the ___________ of illness.

The warm, wet, ____________environment is perfect for plants to grow.