Screw Up

Haiz...Fucking screw up my ohs phase test 2day. First i ans de wrong guess sample. The gas sample is carbon monoixde, i ans it as carbon dioxide. Second i think i do the wrong step for the selection of the pump. Third i cant ans the question tat de teacher give 2 me wooooooow sian. On my way home i feel so stress up, kept wandering if i fail my test, if i nv fail oso get very low marks haiz wish tat i can reverse bac de time 2 take my phase test again. Now is only up to de other test 2 pull up my marks lor ... ok i think i goin 2 cool myself down k bb.