不定项选择An income statement is a summary of revenues and expenses and gains and losses, ending with net income for a particular period of time.
单项选择题循环血液中的凝血块，随血流运行至相应大小的血管，引起管腔阻塞的 A、血栓 B、血栓形成 C、血栓栓塞 D、梗塞
