________ many times，I still didn't know how to operate the machine.
| A．Having taught | B．Having been taught | C．Being taught | D．Teaching |
They say that ___ Chinese language is particularly difficult for ___ European.
| A．the; an | B．/ ; the | C．the; a | D．/ ; a |
— Hey, you haven’t been acting like yourself. Everything OK?
—______ .
| A．I’m fine, thanks | B．Sure, it is | C．That’s good | D．It’s OK |
It was in the garden of his old house ______ he grew up ______ he dug up a pot of gold.
| A．that; that | B．where; where | C．that; where | D．where; that |
The athlete’s years of hard training ______ when she finally won the Olympic gold medal.
| A．cast down | B．got through | C．paid off | D．faded out |
Leave your key with your neighbor _you lock yourself out one day.
| A．as long as | B．in case | C．even though | D．as if |