18.
W: The weather forecast said that we would have another wonderful day tomorrow. Shall we go and climb Mount Tai?
M: Good idea. But we'd better leave very early, or else we'll get caught in the traffic.
Q: What does the man suggest?
解析:D。对于女士的建议(“我们爬泰山怎么样?”),男士说:“好的,但我们得一大早动身,否则就会遇上交通堵塞。”因此D正确。典型的“中But题”。男士在简短回答后,用But提出自己的看法,是解题要点。leave与set off 为同义表达。