It's hard to advise in writing. One idea: if you say the "i" sound correctly in the word "hit" for example, then you can't make it long - you have to finish the sound quickly. If you say "heat", then you can make the "ea" sound as long as you want - heeeeeat.

Yes, their pronunciation in English sounds quite different to a native English-speaker. But don't worry too much about it. The consonants are usually more important than the vowels. If you mispronounce the vowels in a word, not only can we usually guess the word from context, but we will often think we have "heard" the correct vowel. This is particularly true when you are speaking with an accent, because we will get used to the way you pronounce English vowels. There's almost no reason why you would need to say the word "bitch." If you say something sort of in-between "bitch" and "beach," and what you are saying is "I'm going to Nantasket Beach on Saturday," then we will actually think we hear "beach."

beach 的“比”音比 bitch的“比”长一点 如果你不想让别人混淆 你可以故意拉长 beach 的“比”音 bitch 的 比 是短促音 “bi"的“i"基本上不发音 而且说完bi后 还可以故意停顿一下（那个t就是停顿音的意思） 再说ch 而且bitch的 bi 可以发成类似于中文的“别”，后面可以有个小小的“e"音 通常根据上下文 别人也会知道你在说沙滩还是婊子233 所以就算说错了也没关系

Well, for me. I think there is no difference between the two terms of pronounciation. It looks the same but in spelling does.