设血a=12;,则执行完语句a+=a-=a*a;后,a的值是______。
A.522
B.264
C.144
D.-264
参考答案:D
从括号中选择正确的形式填空
1. Zhang Fang can _____ (speak /talk) English. She often _____ (speaks / talks) with Ms King in English.
2. What time does Mr Smith usually _____ (arrive / get to) his office?
3. She _____ (likes / enjoys) to play tennis on weekends.
4. He goes to _____ (Japan /Japanese) in order to improve his _____ (Japan / Japanese).
5. Everyoneis _____ (exciting/ excited), because the speech is _____ (exciting / excited).
6. Judie often _____ (wears /puts on) a white T-shirt and a red skirt, but today she is _____ (putting on / in) a green
T-shirt and a black skirt.
有关环境问题叙述正确的是( )。
A.环境问题是伴随着经济问题而出现的。
B.环境问题在发展过程中产生,但可以在发展达到很高程度之后解决。
C.环境问题主要表现为环境污染和生态破坏两大类。
D.环境问题产生的主要原因是环境本身的自净能力和再生能力太差。