5. What          (happen) if there is no water or air on the earth?

4. While he           ( watch) a video at home，his best friend        (come) to

see him yesterday afternoon.

3. If you        (help) others in trouble，you        (be) happy.

2. When Ann called me，the barber          (cut) my hair.

1. If he        (have) enough time tomorrow,he        (meet) you at his

office.

(   ) 5.1 will go to Lucy’s birthday party if I        .

A. invite    B. am invited

C. am inviting    D. will invite

(   ) 4. Swimming in the lake always makes my mother        about me.

A. to worry    B. worrying

C. worry    D. worries

(   ) 3. Dashan speaks Chinese        for us to understand.

A. good enough    B. enough good

C. well enough    D. enough well

(   ) 2. Get up early or you can’t        the early bus.

A. catch

B. catch up

C. catches

'D. catches up with

(   ) 1. We        go on a picnic if it

       rain tomorrow.

A. don’t;isn’t

B. don’t;stop

C. will； doesn’t

D. aren’t;doesn’t