He’s only too ready to help others, seldom, _____ refusing them when they turn to him.
| A．if ever | B．if never | C．if not | D．if any |
______ the warning message, more visitors might have been trapped in the flood.
| A．Apart from | B．Regardless of | C．Other than | D．But for |
______ to sunlight for too much time will do harm to one’s skin.
| A．After exposed | B．If exposing |
| C．Having exposed | D．Being exposed |
It’s a difficult skill to master, but ______, it will benefit you for the rest of your life.
| A．once obtained | B．when to obtain |
| C．after obtaining | D．while obtaining |
My grandmother has kept the photo ______ she can see it every day for a couple of decades.
| A．which | B．when | C．that | D．where |
Bob is in a hopeless situation, ______ we will keep a very close eye on.
| A．which | B．where | C．that | D．when |