下列说法:①所有等腰三角形都相似;②有一个底角相等的两个等腰三角形相似;③有一个角相等的等腰三角形相似;④有一个角为60°的两个直角三角形相似,其中正确的说法是(). A . ②④ B . ①③ C . ①②④ D . ②③④ 答案:A32、____, this physics problem seemed
quite simple, but when I tried to work it out, I just couldn’t.
A. On one hand B. In
my opinion C. At first sight D. On its own