Smile to the world, ______ the world will smile back to you.
| A．nor | B．but | C．or | D．and |
This advertisement is a/an______ example of their marketing strategy
| A．average | B．specific | C．typical | D．flexible |
We must soon ______a new teacher to the class.
| A．adapt | B．appoint |
| C．exchange | D．abuse |
The tourists, had enjoyed themselves so much in the botanic garden, were worn out。
| A．all of what | B．all of which |
| C．all of them | D．all of whom |
We can hardly believe such a young boy ______ travel around the world all by himself.
| A．may | B．need | C．should | D．must |
My friend Jack was the first person I knew ______an iPhone 5S.
| A．using | B．to use | C．used | D．having used |