MyDataContext dc = new MyDataContext();
            Expression<Func<Order, bool>> c1 = x => x.id >= 4;
            Expression<Func<Order, bool>> c2 = x => x.id < 7;
            Expression<Func<Order, bool>> c3 = c1.And(c2); 
            IQueryable<Order> q1 = dc.Order.Where(c3);
            var l1 = q1.ToList();

public static class PredicateBuilder
    {
        public static Expression<Func<T, bool>> And<T>(this Expression<Func<T, bool>> expr1,
                                                             Expression<Func<T, bool>> expr2)
        {
            var invokedExpr = Expression.Invoke(expr2, expr1.Parameters.Cast<Expression>());
            return Expression.Lambda<Func<T, bool>>
                  (Expression.AndAlso(expr1.Body, invokedExpr), expr1.Parameters);
        }
    }

List<Expression<Func<Order, bool>>> ps = new List<Expression<Func<Order, bool>>>();
            Expression<Func<Order, bool>> c1 = x => x.id >= 4;
            Expression<Func<Order, bool>> c2 = x => x.id < 7;
            Expression<Func<Order, bool>> c3 = x => x.Lines.Count > 2;
            Expression<Func<Order, bool>> c4 = x => x.Customer.Name.Contains("1");
            ps.Add(c1);
            ps.Add(c2);
            ps.Add(c3);
            ps.Add(c4);

            IQueryable<Order> q1 = dc.Order.AndQ<Order>(ps.ToArray());
            var lll = q1.ToList();

public static IQueryable<T> AndQ<T>(this IQueryable<T> query, params Expression<Func<T, bool>>[] predicates)
        {
            return predicates
                .Aggregate(query, (result, predicate) => result.Where(predicate));
        }