_____ ecotourism is becoming popular, we must remain cautious about its adverse effects.

_______ an industrious businessman, he failed to make a profit.

A baby might show fear of an unfamiliar adult, he is likely to smile and reach out to another infant.

– a child can understand it

a deer leapt out in front of me

A reward has been announced for the employees who - hard.

After he (finish) secondary school, he started to study graphic design.

After it was repaired, it -- again.

------- all his attempts to solve the problem, he failed.

Although initial investigations pointed towards him—.