2020-02-24到2020-12-31
第3周——从键盘中来，到键盘中去，开始输入和输出啦 第一次课单元测试-
1、 Which one is an invalid identifier as follows ().
A:abc123
B:No.1
C:123
D:OK
答案: No.1
2、 Which one is a valid identifier as follows ( ).
A:_buy_2
B:2_buy
C:? _buy
D:buy?
答案: _buy_2
3、 Which one is a valid identifier as follows ().
A:int Define WORD