A number of students _____ the sports meeting. The number of the students who take part in ____200.[ ]

A. take part in, is                            

B. takes part in, are  

C. taking part in , are                        

D. taking part in, is

气泡泄漏检测涂复泄漏检测溶液可容许的方法是（）

A．用刷子刷；

B．喷雾器喷涂；

C．喷射瓶喷涂；

D．上述三种方法都可以。