Python无效语法：Print和Elif语句

Question

我是Python和编程的新手（确切地说是2天）。我正在闲着试图想出一个比打印“Hello world”更复杂的过程。我想知道你是否有人能告诉我为什么它标记我的打印和elif语句无效。我正在使用Python 2.7.10，谢谢！

A = raw_input("Do you live in the US or Canada?")
if A == " US" or "Canada":
        print "Welcome!"
else:
    print "We're sorry, but your country is currently not supported!"

B = int(raw_input("How much is your package?")
        if B >= 25
            print "Your shipping is $4.00"
    elif B >= 50
        print "Your shipping is $8.00"
else:
    print "Congrats, your shipping is free!"