This house is quite old. It ________ over 100 years ago.
A. is built
B. were built
C. was built
D. built
Đáp án C
I think we should have our house painting because it looks too dirty.
The situation is serious. Something must ___________ before it’s too late.
Species that have already lost habitat because of deforestation were given higher priority in the plan because of their greater risk of extinction.
The Red List has been introduced to raise people’s _______ of conservation needs.