根據下面各題括號里漢語的提示和句子的意思，寫出恰當形式的英語單詞，每空格只寫一個單詞。
1. Today is Tree Planting Day. The students are ______________ (挖) holes for trees.
2. The shopping-mall is on ______________ (營業) from 9:00 a.m. to 10:00 p.m.
3. He is still sad though his pet dog has been ______________ (死的) for five years.
4. It is hard to ______________ (選擇) between staying with my parents and going abroad.
5. The temperature in Harbin is very low in winter, usually below ______________ (零).
6. The man seemed to be waiting for ______________ (某人) in the building.
7. I heard some noise from the room ______________ (在上面).
8. What a lovely morning! The ______________ (鳥兒) are singing in the trees.
9. Would you please ______________ (郵寄) this letter for me on your way home?
