________ convenient it is to send and receive e-mails on the

題目：

________ convenient it is to send and receive e-mails on the iPhone5!A) What B) How C) What a D) How a Parents should always keep an eye on little children,________ they can easily get hurt.A) so B) but C) and D) or

解答：

B
D
正確答案望採納
再問： 要理由！
再答： 第一題是HOW的用法 第二個or意思是否則