At that time he looked angry because his son______computer games all the afternoon

A．played

B．was playing

C．has played

D．had been playing

小强由妈妈带着到牙防所做窝沟封闭，大夫检查后告诉可以不做，因为小强的牙

A．已有2颗牙患龋

B．等牙齿正畸后再做

C．窝沟不深自洁作用好

D．全口磨牙无龋

E．充填龋齿后再做