It will _____ cold in Harbin. （ ）
A：do
B：be
C：is
The boy has made rapid progress, and he has already ______ in ______ the exam.
若A-4,y1,B-3,y2,C1,y3为二次函数y=x2+4x-5的图象上的三点,则y1、y2、y3的大小关系是____ .
