等腰三角形的一个底角为30°，则顶角的度数是______度．
因为其底角为30°，所以顶角=180°-30°×2=120°．
故填120．
一件商品，先涨价20%，然后又降价20%，结果现价与原价相等．______．
In spoken English of some areas in the US, the "r" sounds at the end of the words().
A. are dropped
B. drop
C. are being dropped
D. have dropped
