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。