下列各组数据中的三个数作为三角形的边长,其中能构成直角三角形的是( )
The manager of the hotel was waiting at the gate _______ the guests arrived.( )
A.whileB.whenC.unlessD.after
Liu Changjian,the command pilot of Sichuan Airlines Flight 3U8633, successfully _______ down the plane last month.( )
A.has broughtB.will bring
C.broughtD.bring
The local guide spoke ______ she could to make the visitors understand her.( )
A.as clear asB.as clearly as
C.so clear asD.so clearly as
I saw John in the park this morning.
It _____ be him. He has gone to HongKong.( )
A.can'tB.canC.mustn'tD.must
_____ do you visit your grandparents, Timmy?
Once a week.( )
A.How manyB.How longC.How muchD.How often