1. Millions of old car tires (throwing/thrown) away every year (can be recycled/ can recycle) to make pipes and floor coverings.
2. Last week, the Browns (were paddling/paddled) around Xuan Huong Lake when it (was started/ started) raining.
3. Mrs. Nga (is getting/ gets) wet now because she (always leaves/ is always leaving) her umbrella at home.
4. It’s expensive (to travel/ travel) to Nha Trang by plane. Would you mind (to go/going) by train?