中文：

定投是一种定期投资策略，通过长期、稳定的投资，降低市场波动带来的风险。那么，定投什么基金呢？

首先，定投可以选择指数基金。指数基金是一种被动型基金，其投资目标是追踪特定市场指数的表现。通过定投指数基金，可以分散投资风险，避免集中投资于某个行业或公司。同时，指数基金的管理费用较低，长期投资收益相对稳定。

其次，定投可以选择债券基金。债券基金是一种相对稳定的投资工具，其收益主要来源于债券利息和债券价格变动。通过定投债券基金，可以在一定程度上降低投资风险，同时获得相对稳定的收益。

最后，定投可以选择混合型基金。混合型基金是一种既投资股票又投资债券的基金，其投资目标是在控制风险的前提下，获得相对稳定的收益。通过定投混合型基金，可以获得资产配置上的平衡，同时获得股票和债券的收益。

总的来说，定投什么基金取决于投资者的风险承受能力、投资目标和市场环境等因素。在选择定投的基金时，需要综合考虑这些因素，选择适合自己的投资工具。

英文：

Investing regularly is a strategy that involves investing a fixed amount of money at regular intervals to reduce the risk of market fluctuations. So, what kind of fund should be invested through regular investing?

Firstly, index funds can be chosen for regular investing. Index funds are passive funds that aim to track the performance of a specific market index. By investing in index funds regularly, investors can diversify their investment risks and avoid investing too heavily in a particular industry or company. Additionally, index funds have lower management fees and relatively stable long-term investment returns.

Secondly, bond funds can be chosen for regular investing. Bond funds are a relatively stable investment tool whose returns mainly come from bond interest and bond price changes. By investing in bond funds regularly, investors can reduce their investment risks and obtain relatively stable returns at the same time.

Finally, mixed funds can be chosen for regular investing. Mixed funds are funds that invest in both stocks and bonds, and their investment goal is to obtain relatively stable returns while controlling risks. By investing in mixed funds regularly, investors can obtain a balance in asset allocation and obtain returns from both stocks and bonds.

Overall, what kind of fund should be invested through regular investing depends on factors such as an investor's risk tolerance, investment goals, and market environment. When choosing the fund for regular investing, investors need to comprehensively consider these factors and choose the appropriate investment tool for themselves.