Question 1: Train

Question 2: Always

Question 3: Catch

Question 4: Monday

Question 5: Kitchen

Test analysis:

The singular noun of the question 1:by+vehicle, so here is the train. We go to Beijing by train.

Question 2: modify the verb phrase go there, so use the adverb always. I always go there by car.

Question 3: The early bird is the singular form of the third person, so the predicate is catches. The early bird catches the worm.

Question 4: What day of the week should be capitalized, so it is Monday here. We held a class meeting on Monday afternoon.

Question 5: In the kitchen, in the kitchen, so it's the kitchen. Where is your mother? She is cooking in the kitchen.