$\text{I.}$

$\text{1.the heavy snow,they wouldn't have been late for the meeting.}$

$\text{But for chỉ dùng cho câu điều kiện loại 2 và 3.Xét câu gốc đang thuộc thì quá khứ nên sẽ chuyển sang câu điều kiện loại 3->chuyển sang But for: But for+N_phrases/V_ing, S+could/would+have+P.P)}$

$\text{2.on her friend not driving too fast. (S+insisted+on (sb)+doing sth : khăng khăng, nài nỉ ai đó làm gì)}$

$\text{3.been a significant improvement in the quality of life of people in the countryside.}$

$\text{4.he was half way through the exercise did he realize how difficult it was. (Only when + clause + Trợ động từ + S + V: Chỉ đến khi.....)}$

$\text{5.its roof blown off by the storm. (have sth done : có cái gì được làm bởi ai)}$

$\text{II.}$

$\text{1.in urgent need of help (urgent : khẩn cấp|need of help : cần sự giúp đỡ }$

$\text{2.bore no resemblance to (no resemblance to sb:không giống cái gì)}$

$\text{3.in no mood to work (to be not in the mood to do sth = to be in no mood to do sth : không muốn làm gì)}$

I.

1. But for the heavy snow, they wouldn't have been late for the meeting.  

2. Ann insisted on her friend not to drive so fast.

3. There has been a significant improvement in the quality of life of people in the countryside.

4. Only when he was halfway through the exercise did he realize how difficult it was.

5. The house had the roof blown off by the storm

II.

1. in urgent need of help

2. bore no resemblance to

3. in no mood to work