said when you think what has been suggested is certainly not, or certainly is, the correct and expected thing

"I bought her some flowers to say thank you." "I should think so too." “我给她买了些花表示感谢。”“当然应该那样。”

"I don't like to drink more than one bottle of wine in an evening." "I should think not." “我不喜欢晚上喝超过一瓶葡萄酒。”“当然不能。”