It’s a duty for friends to ________ each other when they are in trouble.
The teacher asked the students .
Alow-carbon(低碳)lifestyle has an effect our daily life.More and more attention has been paid to Energies these days.
The teachers _________ the office for a few minutes when we arrived.
---Mum,_______ I watch TV? ---No. Unless your homework _______________.
__________terrible luck he had yesterday!