I don’t know the reason he was absent.A、whyB、becauseC、whichD、as

I had to buy _____________ these books because I don’t know which one was the best.A.bothB

– He’s the best in the team. －－ _______________.A、I agree with you.B、I don’t know.C、I’m

He has ______ told me about it. I don’t know why.A: everB: evenC: alreadyD: never

I was out of town at the time, so I don’t know exactly how it _______.A. was happening

I don’t know the origin of this custom.

I don’t know if the pain.ting is authentic