1. In1981 a drug technician at the Centre for Disease Control in the USA, noticed an unusually high number of requests for the drug pentamidine, used to treat Pneumocystis carinii pneumonia (PCP). This led to a scientific report, in effect a case-series study, of PCP occurring unusually in five gay men in Los Angeles. These events signaled the arrival of HIV in the USA.

A. one-shot case study

B. time-series design

C. static group comparison design

D. counter-balanced design

7. The research describes the design having 'regular group' versus 'as-needed salbutamol group' in patients with asthma. Patients took either 200 mg salbutamol from a coded inhaler or placebo four times daily for two weeks. During treatments, 'regular group' gets 200 mg salbutamol and the 'as-needed salbutamol group' gets placebo. Patients were instructed to record/measure their peak expiratory flow rate (PEFR). After a wash-out period to prevent drug effect carry-over, 'regular group' gets placebo and 'as-needed group gets 200 mg salbutamol for the same period of time. The PEFR were then recorded.

A. one-shot case study

B. time-series design

C. static group comparison design

D. counter-balanced design

choose the corect option just no need of explanation