答案:A
____ to Anne's birthday party, Mr. Brown is now searching shop after shop for a nice present for her.
A.Having invited
B.Having been invited
C.Have been invited
D.Being invited
血浆中主要的天然抗凝物质有()
A.肝素
B.纤维蛋白溶解酶
C.抗凝血酶III
D.柠檬酸钠
E.Ca2+