1. Snow falls when the temperature(温度)in the air is at or below(低于) ℃.
A. 0 B. -10 C. 10
2. Snowflakes(雪花)can come in different shapes(形狀), like .
A. Needles(针) B. stars C. both A and B
3. We cant see snow in .
A. Canada B. The US
C. Singapore(新加坡)
4. No two snowflakes are the same.
A. True B. False
(答案请见P48)