Global warming is a serious issue, and we must take steps to __________ it from growing further.

Key __________ of the Siberian tiger are Korean pine forests with a complex composition and structure.

The government must take tougher __________ on pollution from cars.

These weapons are not only toxic but can also __________ habitats through fire.

Mark said he (had written / was writting) several articles on sporting events since March.

She said she would visit her grandfather's farm the (following / previous) week.

She asked me (if I had / if had I) bought a second-hand piano two days before.

Ellie said her husband had gone with her to the show the (next / previous) day.

They told me they were meeting at the café this afternoon.

They asked me whether had I worked from home the previous year.

Ellie asked me that when I was going to return the book.