苯a,呋喃b,吡咯c,噻吩d发生亲电取代反应的活性次序是()。
A. a>b>c>d
B. b>a>c>d
C. d>c>b>a
D. c>b>d>a
能与马来酐发生Diels-Alder反应的是()。
A. 呋喃
B. 噻吩
C. 苯
D. 吡啶
Erythrocyte is the scientific name for a:
A. white blood cell
B. lymphocyte
C. red blood cell
D. muscle cell
Platelets, or thrombocytes, are involved in:
A. inflammation
B. digestion
C. immunity
D. blood clotting