第4题: [单项选择]Which of the following is NOT TRUE of the current situation in Sri Lanka A. Students have difficulty in finding jobs. B. There exists an internal strife. C. The economy is in a recession. D. The economy is developing rapidly. 参考答案:D
第5题: [多项选择]溢流的绝对信号()。 A. 循环池液面增加 B. 返速增加或停泵时井涌 C. 关井地面压力显示 参考答案:A, B, C