____ I went to the seaside, I picked up a great many shells.
| A．The first time | B．For the first time | C．At first | D．By the first time |
In the U.S, ______a tip is thought to be polite when paying the bill.
| A．leave | B．having left | C．leaving | D．being left |
He is the only one of those clerks ________ to the important conference.
| A．who was inviting | B．who were invited |
| C．who has been invited | D．who have been invited. |
When I turned to Tony for help, I found that the more he tried to explain, ___________.
| A．the more I became confused. | B．the more confused became I |
| C．the more confused I became | D．I became more confused. |
The two boys share the same hobbies but they are quite different _______ personality.
| A．in | B．with | C．for | D．on |
It won’t be a very long time _________ he is in business for himself.
| A．until | B．when | C．before | D．that |