下面哪个是不易发生龋坏的
A．下颌前牙舌面B．上颌切牙邻面区C．上颌侧切牙舌窝D．后牙窝沟点隙E．下颌牙颊侧
参考答案：A
1到200这200个数中既不是2的倍数，又不是3的倍数，也不是5的倍数的自然数共有______个．
You aren’t supposed to ask the boy to buy things for you. _______, he is too young.
A．In general
B．After all
C．To my surprise
D．To start with
