Можно вот так
1) It's difficult to find a job if you don't have basic computer skills, which is very common job requirement now
2) English has practically become the world's international language, which is convenient for English-speaking counties.
3) Some countries refuse to sign a ban on producing chemical weapons, which is a very inhumane.
4) The 2008 Olympics will be held in China, which has long-lasted excellent records in sport.