上海—120、6135发动机喷油提前角在上止点前()mm。
A.10~15
B.15~20
C.20~25
D.28~31
参考答案:D
用所给单词的适当形式填空
1. He plays the guitar very (good).
2. Xiaoming eats lots of (health)food.
3. Sandra (have) two eggs and a glass of milk every day.
4. Tom (not like) apples.
5. I (like) hamburgers,but I (not like) pears.
有关我国地形的说法,正确的是( )
A.我国地形复杂多样,山区面积广大
B.我国地形类型单一,以平原为主
C.地势东高西低,呈阶梯状分布
D.地势第二级阶梯的地形以盆地和平原为主