Nelson Mandela, former president of South Africa, devoted himself        to making the black and white equal.

It was difficult being in a foreign country, ________ if you don’t speak the language.

I have searched ________ for the book but couldn’t find it.

—Jenny,they say you have asked for a leave because of a sudden headache.I’m worried about you,and are you ________better now?—I’m all right now,thanks for your care.

—Where have you been? —I got caught in the traffic jam; ______ I’m here just on time.