The Chinese abacus(算盘), officially ______ as a cultural heritage at the 8th Annual UNESCO World Heritage Congress, is another symbol of Chinese wisdom.
I saw some trees the leaves of _____ were black with disease.
Their problem today is somewhat similar to _____ they faced many years ago.
Dorothy was always speaking highly of her role in the play, ____, of course, made the others unhappy.
He made another wonderful discovery, ______ of great importance to science.
He’s got himself into a dangerous situation _____ he is likely to lose control over the plane.