容量瓶的使用操作包括哪些步骤（）
A. 检漏
B. 转移溶液
C. 初步混匀
D. 定容
E. 摇匀
Which of the following is known as the heart and brains of a computer?
A. Optical drive
B. Motherboard
CPU
D. Memory
The ________ is a group of microchips on the motherboard that control the flow of data and instructions sent to and from the processor.
A. PCIe
B. Chipset
C. RAM
D. CPU
微信支付 
支付宝支付