请教:Do you know _____ we'll go get there at3:00 this afternoo
请教:Do you know _____ we'll go get there at3:00 this afternoon? A:Do you know _____ we'll go get there at3:00 this afternoon? B:I am afraid we'll be late. A.that B.How C.Why D.whether 这道选哪个,为什么?