—Is there anything wrong with you, Jake? You look so pale．

—I feel very tired．I _____on this boring paper every day so far this month．

A．work

B．have been working

C．had been working

D．am working

硫喷妥在体内的代谢路径主要为

A．脱氨基化

B．脱硫氧化

C．S-氧化

D．羟化

E．S-烷基氧化