I didn't know _____．（ ）
| A． |
what we could do |
| B． |
how we could do |
| C． |
what can we do |
For your own______，please don′t smoke on the plane．（ ）
| A． |
feelings |
B． |
safety |
C． |
health |
Class， please teach______the article we will learn tomorrow．（ ）
| A． |
yourselves |
B． |
yourself |
C． |
ourselves |
______on the grass． It's a rule of the park．（ ）
| A． |
Step |
B． |
Don' t step |
C． |
To step |
﹣﹣﹣Excuse me， will the flight arrive soon？
﹣﹣﹣Yes， It will be landing right______．（ ）
| A． |
at times |
B． |
in time |
C． |
on time |
﹣﹣﹣What did you learn in geography class yesterday？
﹣﹣﹣I learned that the sun______in the east．（ ）
| A． |
was rising |
B． |
rises |
C． |
rose |