3. He was in the kitchen at that time. He was helping his mother.(合并為一句) 

He in the kitchen his mother at that time.

2. He was drinking coffee when his sister bought some food.(改為同義句)

 he was drinking coffee,his sister some food.

1. The girl was waiting for a bus when it began to rain.(對畫線部分提問) 

 the girl when it began to rain?

5. 直到風逐漸減弱她才出去。

She didn't go out until the wind was .

4. 我昨天晚上直到11點才睡著。

I didn't  until 11 last night.

3. 昨天晚上七點他在看電視。

He  TV at seven yesterday evening/last night.

2. 他在等公共汽車時遭到了襲擊。

He was attacked while he  for a bus.

5. —What you ( do) when he arrived?

—I (write) a letter at that time.

4. (2015 •江蘇常州)

一Why didnH you watch Running Man on TV?

—I (make) up the music for the coming School Art Festival.

3. After the storm,he found many (fall) trees on the road.