开发控制是对用户的【 】加以控制和协调。
参考答案：并发操作
解析：并发控制是对用户的加以并发操作控制和协调。
Please tell them _________ here. It’s dangerous.
A．to park
B．don’t park
C．not park
D．not to park
The accident _____ on the morning of last Monday. [ ]
A. was happened
B. was taken place
C. took place
D. happening
