你去鄰居家玩，看見鄰居家裏養的植物一片繁榮景象，真是一日不見如三秋兮，（亂用成語~~）於是你不禁讚歎說：
“和我上次來的時候比你們家植物長大了好多啊。”
Your plants have ______ a lot since my last visit.
A grown up B grown
我們來看看這兩種說法有什麼不同。
上圖：Your plants have grown up a lot since my last visit.
上圖：Your plants have grown a lot since my last visit.
答案就是B咯。
People grow up, when they get older and stoping behaving like children. Here you are talking about something getting bigger, you don't need a preposition here.
只有人才用grow up的.，表示人長大了，不會再有小孩子的行爲了，如果表示什麼東西變大了，不需要介詞，這裏用grow就好咯。