我国的西双版纳终年高温多雨，叶片终年常绿，大部分植物都很高大，其植被类型为（  ）

词汇运用
⑴No one is____ （允许）to drive after drinking.
⑵As soon as I arrived in Hong Kong, I sent a ____ （信息）to Mum.
⑶About two hundred people ____ ( 死 )in Ya'an Earthquake on April 20^th .
⑷The moon light shines in ____(通过) the window and the room seems quiet and beautiful.
⑸The teacher spent a long time ____ (解释)the problem to the boys after class.
⑹Now Father's Day becomes very popular. It is on the ____ (three) Sunday every June.
⑺Teenagers should be encouraged to make decisions by ____ (they).
⑻It's much ____ (sun) this weekend. Why not go camping, David? ——Sounds great.
⑼Everyone likes Mary in our class because she always talks to others____  (polite).
⑽The telephone was one of the most important ____ (invent) of the 19th century.

男低音独唱时由女高音轻声伴唱，下面对二人声音的描述正确的是（  ）

如果(x+m)(x+n)展开后不含x的一次项，那么m、n的关系是                   （　  ）