题目内容：
Conventional IVF procedures include （）
A.Gonadotropin is used to stimulate the development of multiple follicles.
B.The development of follicles are monitored by blood endocrine hormones tests and B-ultrasound.
C.When follicles grow to mature, chorionic gonadotropins are injected to trigger for final maturation.
D.After 36 hours, B-ultrasound-guided puncture will be performed to mature follicles.
参考答案：