一旦发现有人触电，应立即采取把触电者送往医院抢救措施。
参考答案：错
Scientists are convinced _____the positive effect of laughter _____physical and mental health．
A．of ;on
B．by; in
C．of ; at
D．on ;at
根据花卉的生长发育特点，简述一、二年生花卉在我国南北方的适宜播种期。
