C
D

I met them when I was in Paris. It was in 1990. (We use the simple past tense "was" for a specific time in the past)
I will finish my homework before I go to bed. (Correct sentence structure: future tense with "will" + present base verb)
There isn't any sugar left in the kitchen. (Singular subject "sugar" requires singular verb "isn't" and singular indefinite article "any")
We are interested in going to the beach in Mexico. ("Interested on" is not common, use "in")
My brother will open the fridge as soon as he arrives home. ("As well as" implies addition, not timing. Use "as soon as" for immediate action)
I'm keen on traveling to visit other places. ("Keen into" is not common, use "on")
Some of the agricultural practices today are responsible for fostering desertification. (Subject-verb agreement: "practices" is plural, so verb needs to be plural "are")
Do you have a minute? I'd like to tell you about something. ("Telling to" is not natural. Use "to tell")
She won't enjoy the trip until you tell her what happened a few days ago. ("Untill" is misspelled, use "until". "Some days ago" is more natural than "a few days ago" in this context)
I was keen on enjoying my time with my family in London last week. (Correct sentence)
It probably will rain when you get back tonight. (Correct sentence)
Your shoes will be ready in twenty minutes. (Use "be" with future tense for state of being)



 

4.C
5.D
6.A
7.C
8.C
9.D
10. C
11.C
12.A