一般环境问题的基本特点是（）
A.复杂性
B.广泛性
C.潜在性
D.累积性
参考答案：A, B, C, D
传染性非典型肺炎主要传播途径是
A．飞沫 B．血液 C．性接触 D．消化道 E．母婴
用所给单词的正确形式填空
1. You are a _____ (bear) writer.
2. _____ (unite) , we stand ; divided, we fall.
3. The teacher stood there, _____ (surround)by a group of students.
4. _____ (see)from the hill, the school looks like a park.
5. _____ (lose)in the forest,he was scared to death.
