选词填空（每词只能用一次）。

cold, cool, warm, surprised, relaxed

1. She is ______ she can play the guitar well.

2. The boy in sun-glasses (太阳镜) looks ______ very much.

3. It‘s very ______ in spring.

4. It is ______, please wear your scarf.

5. The boys are really ______ in the park.

四行程活塞式发动机，在哪个或哪几个行程两个气门同时打开（）.

A.排气行程

B.进气行程

C.膨胀行程和进气行程

D.排气行程和进气行程