问题
                    
_____did the space flight last? —Twenty-one hours.[ ]
                            A:How many
B: How long
C: How soon
D: How often
                        
                        B: How long
C: How soon
D: How often
正确答案是:
                         
                        
                        
                    同类题型
                    He likes milk and eggs _______ breakfast. [ ]
Whose model plane is it? —-It’s ________.
My dress is the same __________ Lily’s, but it’s different __________ Lucy’s.[ ]
Would you mind ______ the door? It’s cold outside.— OK. I’ll do it right now.
Volunteering our time to help people ________ a good way to _______our free time.