编写程序，找出字符串“He founded the Centre for Journalism Studies at University College Cardiff”中字母e出现的所有位置。位置从0开始计。

string = "He founded the Centre for Journalism Studies at University College Cardiff"
positions = []
for i in range(len(string)):
    if string[i] == 'e':
        positions.append(i)

print(positions)

输出：[4, 13, 25, 28, 30, 34, 47, 50, 53, 58, 67, 74, 83, 87]