44. If there isn’t enough rain, the hydropower station can not operate. A. When there isn’t enough rain, the hydropower station can operate. B. Unless there is enough rain, the hydropower station can operate. C. Unless there isn’t enough rain, the hydropower station can not operate. D. Unless there were enough rain, the hydropower station couldn’t operate. 45. If we don’t save water, we will have to suffer from water shortage. 1. A. Unless we don’t save water, we will have to suffer from water shortage. 2. B. If we save water, we will have to suffer from water shortage 3. C. Unless we don’t save water, we won’t have to suffer from water shortage 4. D. If we save water, we won’t have to suffer from water shortage. 46. She is too weak; she can’t sit up and talk to you. A. If she weren’t too weak, she could sit up and talk to you. B. If she hadn’t been too weak, she could sit up and talk to you B. If she isn’t too weak, she can sit up and talk to you C. If she wasn’t too weak, she can sit up and talk to you 47. I am too old now; otherwise, I will apply for that post. A. If I would not be too old, I would apply for that job. B. If I was not be too old, I will apply for that job. C. If I were not too old, I would apply for that job. D. If I am not too old, I will apply for that job. 48. I didn’t have enough money with me then; otherwise I wouldn’tl buy that coat. A. If I didn’t have enough money with me then, I would buy that coat. B. If I had had enough money with me then, I would have bought that coat. C. If I had enough money with me then, I wouldn’t buy that coat. D. If I didn’t have enough money with me then, I wouldn’t buy that coat. 49. It’s raining and they can’t go camping in the mountain. A. If it was raining, they could go camping in the mountain. B. If it isn’t raining, they could go camping in the mountain. C. If it weren’t raining, they could go camping in the mountain. D. If it is raining, they could go camping in the mountain. 50. They got success since they took my advice. A. They took my advice, and failed. B. If they did not take my advice, they would not get success. C. But for taking my advice, they would not have got success. D. My advice stopped them from getting success.