–Look at that girl! Is it Susan? --No, it _______ be her. She went to her hometown just now.

—Look at that girl! Is it Susan?—No, it _______ be her. She has gone back to her hometown.

(2014·济南市名校第四次诊断性测试)—Is the letter from your mother?—Yes.But she ________the letter herself，because she doesn’t even know one word.

If you spend the spring sneezing, take a look at your plate. Some foods _____ make allergies worse.

This printer is of good quality. If it ________ break down within the first year, we would repair it at our expense.