问题补充：
pleasant trip it is! I think I will never forget it .
A. How
B. How a
C. What a
D. What
答案：
A. How
B. How a
(答案→)C. What a
D. What
解析：以what引导的感叹句的基本句型结构为what a/an +adj+可数名词单数+主语+谓语！；what+adj+可数名词的复数/不可数名词+主语+谓语！以how引导的感叹句的基本句型结构为how+adj/adv+主语+谓语！
