Cambridge ________ about 100,000 people. [ ]
A. has
B. have
C. had
D. is
答案：A
—We can use QQ to talk with each other online.
—Really? Could you show me _____ it? [ ]
A. what to do
B. how to do
C. when to do
D. why to do
纤溶酶原激活物的作用是（）。
A.使纤维蛋白原变为纤维蛋白原降解产物
B.使纤维蛋白变为纤维蛋白降解产物
C.使纤维蛋白原变为纤维蛋白
D.抑制纤维蛋白单体变为纤维蛋白
E.使纤溶酶原变为纤溶酶
