These animals are in danger．We should think ______ to protect them．
| A．how we can do | B．how can we do |
| C．what we can do | D．what can we do |
Either you or I ______ going there tomorrow．
| A．is | B．be | C．are | D．am |
Our English teacher is kind ________ helpful.
| A．and | B．or | C．but | D．so |
As a doctor, you can’t be ________ careful．
| A．to | B．too | C．also | D．very |
--- Tom, would you please not make so loud noise? Dad is sleeping. ---- _________, mom.
| A．Yes, I know | B．OK, I know |
| C．Sorry, I won’t | D．Sorry, I will |