There are a lot of cookies in the kitchen, for example. So think about plural noun and the plural form of is or are in the singular as well. So this is a very common one. Be careful of that.
There are a lot of cookies in the kitchen.这是一个非常常见的问题。要小心。
Laird added that scientists need to be careful of the mutations and mistakes that may be introduced in the method before using stem cells to make eggs.